human
***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Study Design . A prospect i ve clinical and radiologic investigation of two groups of patients presenting with either acute back pain only or acute leg pain only , yet similar restriction in straight leg raising ( SLR ) . Objectives . To highlight a group of patients presenting with acute low back pain only , yet a restricted SLR normally associated with leg pain ( sciatica ) caused by a posterolateral disc prolapse . To determine the anatomic source of the pain in the low back pain only group . Summary of Background Data . A restricted SLR is commonly associated with leg pain ( sciatica ) due to compression of a nerve root by an intervertebral disc prolapse . Previous studies investigating pain patterns on SLR have suggested that central disc prolapses tend to induce back pain whereas the more lateral prolapses induce leg pain . Such research work has involved patients presenting with typical sciatic pain investigated by myelography and undergoing decompressive surgery . There are no studies specifically investigating patients presenting with low back pain only and reduced SLR . Methods . Two groups of patients , one with acute low back pain only and one with acute leg pain only , yet showing similar restriction in SLR underwent MR imaging .  The scans were review ed “ blind ” by an experienced spinal radiologist and imaging features recorded according to a detailed protocol . The MR findings were then compared . Results . Significant disc prolapses were seen equally in both groups . The disc prolapses in the back pain only group were more likely to be central , smaller , to compress the theca only , and to be at a higher lumbar level as compared with the leg pain only group . Conclusions . Acute low back pain associated with significant restriction in SLR is likely to be caused by a disc prolapse compressing the anterior theca Study Design . Prospect i ve cohort study of r and omly selected Veterans Affairs ( VA ) out patients . Objective . To determine the prevalence of  magnetic resonance imaging ( MRI ) findings in the lumbar spine among persons without current low back pain or sciatica and to examine which findings are related to age or previous back symptoms . Summary of Background Information . Previous studies of patients without low back pain have not explored the possible association of various MRI findings to past symptoms . Methods . We r and omly selected an age-stratified sample of subjects without low back pain in the past 4 months from clinics at a VA hospital . We collected information on demographics , comorbidity , functional status , and quality of life .  MR images were obtained using a st and ardized protocol through each of the five lumbar disc levels . Results . Of 148 subjects , 69 ( 46 % ) had never experienced low back pain .  There were 123 subjects ( 83 % ) with moderate to severe desiccation of one or more discs , 95 ( 64 % ) with one or more bulging discs , and 83 ( 56 % ) with loss of disc height . Forty-eight subjects ( 32 % ) had at least one disc protrusion and 9 ( 6 % ) had one or more disc extrusions . Conclusion . Many MR imaging findings have a high prevalence in subjects without low back pain . These findings are therefore of limited diagnostic use . The less common findings of moderate or severe central stenosis , root compression , and extrusions are likely to be diagnostically and clinical ly relevant STUDY DESIGN A prospect i ve 9-year follow-up study involving r and omized matched subgroups of 15-year-old schoolchildren with or without low back pain at baseline . OBJECTIVES To evaluate the long-term persistence of initially reported recurrent low back pain , and to examine the significance of abnormalities found in magnetic resonance imaging of lumbar discs in individuals 15 and 18 years of age as possible contributors to persistently recurrent low back pain . SUMMARY OF BACKGROUND DATA In surveys among children and teenagers during the past few years , as many as half of all children in a community report a history of low back pain . The current results , in accordance with previous findings , indicate that there is a subgroup of adolescents with more chronic symptoms which , in the authors ' opinion , deserves more attention . Disc disease accompanying low back pain is a key issue both in research and clinical practice . The significance of early degenerative findings in the lumbar discs is not known . METHODS In the survey of 14-year-olds ( n = 1503 ) , a subgroup ( 7.8 % ) with recurrent low back pain was found . A r and om sample of individuals with recurrent low back pain ( n = 40 ) and an equal number of completely asymptomatic control subjects were selected for a comparative study . The selected groups were examined by magnetic resonance imaging at 15 and 18 years of age . The participation rate of youth at 14 , 18 , and 23 years of age for all three question naires was 82 % ( 29 boys and 33 girls ) . Imaging data were interpreted by two blinded radiologists experienced in low-field-strength magnetic resonance imaging . In calculations of relative risks , the participants reporting recurrent low back pain in all phases of the study were compared with participants who had no persistently recurrent pain . RESULTS Eleven participants ( 35 % ) in the original group with low back pain persistently reported recurrent pain . In 15-year-old participants with disc degeneration , the relative risk of reporting recurrent low back pain up to the age of 23 years was 16 ( 95 % confidence interval 2.2 - 118 ) compared with those having no disc degeneration . In addition , disc protrusion and Scheuermann-type changes at 15 years contributed to the risk of persistently recurrent low back pain . CONCLUSIONS The authors ' earlier findings already favored the hypothesis of a causal relation between the early evolution of a degenerative process of lower lumbar discs and recurrent low back pain in the near future . The current results further strengthen this hypothesis , indicating that individuals with disc degeneration soon after the phase of rapid physical growth not only have an increased risk of recurrent low back pain at this age , but also a long-term risk of recurrent pain up to early adulthood OBJECTIVE To assess the relations between clinical ly recognized lumbar spinal stenosis and the conclusions of masked radiologists and electrodiagnosticians . DESIGN Prospect i ve , masked , double-controlled trial . SETTING University spine center . PARTICIPANTS One hundred fifty persons age 55 to 80 years with or without back pain and with or without magnetic resonance imaging (MRI)-demonstrated stenosis , screened for neuropathy risk , previous surgery , or cancer . INTERVENTIONS Question naires on pain and function ; ambulation testing and physical examination ; and masked electrodiagnotics and MRI . MAIN OUTCOME MEASURE Diagnostic impressions of the examining clinician , radiologist , and electrodiagnostician . RESULTS Following application of post hoc exclusion criteria and elimination of patients due to incomplete or inadequate test data , the clinical diagnosis was lumbar stenosis in 50 subjects , back pain in 44 subjects , and no pain in 32 subjects . Radiologic and clinical impression had no relation ( P = .80 vs asymptomatic , P = .99 vs back pain controls ) . Electrodiagnostic impression trended to relate to clinical impression ( P = .14 vs asymptomatic , P = .09 vs back pain ) . Retrospective application of age-related electrodiagnostic norms for paraspinal electromyographic and limb motor unit changes , established in this study , reclassified 13 of the 17 asymptomatic persons whom the electrodiagnostician thought had stenosis . The clinical impression did correspond to history and physical examination findings typically associated with spinal stenosis and to the independent impression of a neurosurgeon who examined MRI and clinical , but not to the electrodiagnostic data . CONCLUSIONS The impression obtained from an MRI scan does not determine whether lumbar stenosis is a cause of pain . Electrodiagnostic consultation may be useful , especially if age-related norms obtained in this study are applied Study Design . Prospect i ve comparative study of pain drawings with findings on lumbar spine magnetic resonance imaging . Objectives . To assess the ability of the  pain drawing  to predict the presence of nerve root compression . Summary of Background Data . Most research work has concentrated on the ability of the pain drawing to act as a screening method for psychological distress with less work directed at the influence the anatomic abnormality has on the pain drawing . Methods . One hundred thirty‐four consecutive out‐ patients attending for lumbar magnetic resonance imaging in the investigation of back and leg pain completed pain drawings and psychological testing immediately before the examination . The pain drawing was analyzed by previously reported criteria , and the magnetic resonance imaging was assessed independently for the presence of nerve compression by three radiologists . Multivariate stepwise discriminant analysis was used to identify patients with nerve compression on the basis of their pain drawing . Results . Nerve compression was predicted by numbness in the anterolateral aspect of the foot . There was considerable overlap in the appearances of the pain drawings between patients with and without nerve compression , and the pain drawing correctly classified only 58 % of patients with nerve compression . Conclusions . The pain drawing is not a good predictor of nerve compression on magnetic resonance imaging in a group of patients investigated for back and leg pain . It should be interpreted with caution and in light of the full clinical picture Background : An association has previously been reported between finger blanching and hearing difficulties , but only in workers with exposure to noise and h and transmitted vibration ( HTV ) . Aims : To explore the association in a community sample , including cases who lacked occupational exposure to noise or HTV . Method : A question naire was mailed to 12 606 subjects aged 35–64 years , chosen at r and om from the age – sex registers of 34 British general practice s. Inquiry was made about years of employment in noisy jobs , lifetime exposure to HTV , hearing difficulties and tinnitus , and lifetime history of cold induced finger blanching . Subjects were classed as having severe hearing difficulty if they used a hearing aid or found it difficult or impossible to hear conversation in a quiet room . Associations of finger blanching with hearing difficulties and tinnitus were analysed by logistic regression . Results : Among 8193 respondents were 185 who reported severe hearing difficulty and 1151 who reported finger blanching .  After adjustment for age and years of work in noisy jobs , hearing difficulty was about twice as common in men and women who reported finger blanching , including those who had never been importantly exposed to noise and in those never exposed to HTV . Conclusions : These data support an association between finger blanching and hearing loss , which is not explained by confounding occupational exposure to noise , and suggest that it may extend to causes of blanching other than vibration induced white finger . Further investigations are warranted to confirm the association and explore possible mechanisms , such as sympathetic vasoconstriction in the cochlea Study Design This was a prospect i ve study of patients ( study group ) with symptomatic disc herniations and asymptomatic volunteers ( control group ) matched for age , sex , and work-related risk factors . Objective To determine the prevalence of disc herniation in a matched group of asymptomatic volunteers and to access the diagnostic accuracy of magnetic resonance imaging , work perception , and psychosocial factors in identifying symptomatic disc herniations . Summary of Background Data Disc herniations have been reported to occur in 20–36 % of asymptomatic volunteers . A valid comparison of asymptomatic individuals and patients with disc herniations has not been performed . Methods Forty-six patients with low back pain and sciatica severe enough to require a disceclomy were compared with 46 age- , sex- , and risk factor-matched ( heavy lifting , twisting and bending , vibration , and sedentary activity ) asymptomatic voluteers .  Both groups had a complete clinical and magnetic resonance imaging examination and completed a question naire to assess differences in the psychosocial and work perception profiles . The prevalence and the severity of morphologic alterations ( disc herniation , disc degeneration , and neural compromise ) was analyzed by two independent radiologists in a blinded fashion . Differences between both groups regarding MRI findings , work perception ( occupational mental stress , intensity of concentration , job satisfaction , and job-related resignation ) and psychosocial factors ( anxiety , depression , self-control , social support , and marital status ) were compared using multivariate techniques . Stepwise discriminate analysis was used to identify the best discriminating variables within the magnetic resonance image , work perception , and psychosocial categories in terms of the diagnostic accuracy to predict group membership ( study [ pain ] or control [ no pain ] group ) . Results Matched controls had significantly more risk factors than a group of normal individuals . The present study has presented evidence that an age- , gender- , and occupational risk factors-matched group of asymptomatic patients shows a high incidence rate of disc herniations ( 76 % ) . Although significantly less than the symptomatic group incidence of 96 % , this represents a much higher prevalence rate than generally expected and reported in other studies of unmatched asymptomatic volunteers . Patients had more severe disc herniations ( disc extrusions ) than asymptomatic volunteers ( 35 % vs. 13 % ) . There was no significant differences regarding disc degeneration between both groups ( 96 % vs. 85 % ) . The only substantial morphologic difference between both groups was the presence of a neural compromise ( 83 % vs. 22 % ) , which was highly significant ( P < 0.0001 ) . There were significant differences between both groups regarding work perception ( occupational  mental stress , intensity of concentration , job satisfaction , and resignation ; P<0.027 ) and psychosocial factors ( anxiety , depression , self-control , marital status ; P<0.0001 ) . The best single predictor of a group membership was the extent of neural compromise . A combination of this factor with occupational mental stress , depression , and marital status was the best predictive model . With this model , the false-negative rate ( potential overtreatment of disc morphology ) was reduced by more than half compared with morphologic factors ( nerve root compression ) alone ( 22 % vs. 11 % ) . Conclusions . In an age- , sex- , and risk factormatched group of asymptomatic individuals , disc herniation had a substatially higher prevalence ( 76 % ) than previously reported in an unmatched group . Individuals with 
    Output:
    
agent
MRI findings of disc protrusion , nerve root displacement or compression , disc degeneration , and high intensity zone are all associated with LBP , but individually , none of these abnormalities provides a strong indication that LBP is attributable to underlying pathology .
This limits their value in refining epidemiological case definitions for LBP
***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Study Design . A prospect i ve clinical and radiologic investigation of two groups of patients presenting with either acute back pain only or acute leg pain only , yet similar restriction in straight leg raising ( SLR ) . Objectives . To highlight a group of patients presenting with acute low back pain only , yet a restricted SLR normally associated with leg pain ( sciatica ) caused by a posterolateral disc prolapse . To determine the anatomic source of the pain in the low back pain only group . Summary of Background Data . A restricted SLR is commonly associated with leg pain ( sciatica ) due to compression of a nerve root by an intervertebral disc prolapse . Previous studies investigating pain patterns on SLR have suggested that central disc prolapses tend to induce back pain whereas the more lateral prolapses induce leg pain . Such research work has involved patients presenting with typical sciatic pain investigated by myelography and undergoing decompressive surgery . There are no studies specifically investigating patients presenting with low back pain only and reduced SLR . Methods . Two groups of patients , one with acute low back pain only and one with acute leg pain only , yet showing similar restriction in SLR underwent MR imaging .  The scans were review ed “ blind ” by an experienced spinal radiologist and imaging features recorded according to a detailed protocol . The MR findings were then compared . Results . Significant disc prolapses were seen equally in both groups . The disc prolapses in the back pain only group were more likely to be central , smaller , to compress the theca only , and to be at a higher lumbar level as compared with the leg pain only group . Conclusions . Acute low back pain associated with significant restriction in SLR is likely to be caused by a disc prolapse compressing the anterior theca Study Design . Prospect i ve cohort study of r and omly selected Veterans Affairs ( VA ) out patients . Objective . To determine the prevalence of  magnetic resonance imaging ( MRI ) findings in the lumbar spine among persons without current low back pain or sciatica and to examine which findings are related to age or previous back symptoms . Summary of Background Information . Previous studies of patients without low back pain have not explored the possible association of various MRI findings to past symptoms . Methods . We r and omly selected an age-stratified sample of subjects without low back pain in the past 4 months from clinics at a VA hospital . We collected information on demographics , comorbidity , functional status , and quality of life .  MR images were obtained using a st and ardized protocol through each of the five lumbar disc levels . Results . Of 148 subjects , 69 ( 46 % ) had never experienced low back pain .  There were 123 subjects ( 83 % ) with moderate to severe desiccation of one or more discs , 95 ( 64 % ) with one or more bulging discs , and 83 ( 56 % ) with loss of disc height . Forty-eight subjects ( 32 % ) had at least one disc protrusion and 9 ( 6 % ) had one or more disc extrusions . Conclusion . Many MR imaging findings have a high prevalence in subjects without low back pain . These findings are therefore of limited diagnostic use . The less common findings of moderate or severe central stenosis , root compression , and extrusions are likely to be diagnostically and clinical ly relevant STUDY DESIGN A prospect i ve 9-year follow-up study involving r and omized matched subgroups of 15-year-old schoolchildren with or without low back pain at baseline . OBJECTIVES To evaluate the long-term persistence of initially reported recurrent low back pain , and to examine the significance of abnormalities found in magnetic resonance imaging of lumbar discs in individuals 15 and 18 years of age as possible contributors to persistently recurrent low back pain . SUMMARY OF BACKGROUND DATA In surveys among children and teenagers during the past few years , as many as half of all children in a community report a history of low back pain . The current results , in accordance with previous findings , indicate that there is a subgroup of adolescents with more chronic symptoms which , in the authors ' opinion , deserves more attention . Disc disease accompanying low back pain is a key issue both in research and clinical practice . The significance of early degenerative findings in the lumbar discs is not known . METHODS In the survey of 14-year-olds ( n = 1503 ) , a subgroup ( 7.8 % ) with recurrent low back pain was found . A r and om sample of individuals with recurrent low back pain ( n = 40 ) and an equal number of completely asymptomatic control subjects were selected for a comparative study . The selected groups were examined by magnetic resonance imaging at 15 and 18 years of age . The participation rate of youth at 14 , 18 , and 23 years of age for all three question naires was 82 % ( 29 boys and 33 girls ) . Imaging data were interpreted by two blinded radiologists experienced in low-field-strength magnetic resonance imaging . In calculations of relative risks , the participants reporting recurrent low back pain in all phases of the study were compared with participants who had no persistently recurrent pain . RESULTS Eleven participants ( 35 % ) in the original group with low back pain persistently reported recurrent pain . In 15-year-old participants with disc degeneration , the relative risk of reporting recurrent low back pain up to the age of 23 years was 16 ( 95 % confidence interval 2.2 - 118 ) compared with those having no disc degeneration . In addition , disc protrusion and Scheuermann-type changes at 15 years contributed to the risk of persistently recurrent low back pain . CONCLUSIONS The authors ' earlier findings already favored the hypothesis of a causal relation between the early evolution of a degenerative process of lower lumbar discs and recurrent low back pain in the near future . The current results further strengthen this hypothesis , indicating that individuals with disc degeneration soon after the phase of rapid physical growth not only have an increased risk of recurrent low back pain at this age , but also a long-term risk of recurrent pain up to early adulthood OBJECTIVE To assess the relations between clinical ly recognized lumbar spinal stenosis and the conclusions of masked radiologists and electrodiagnosticians . DESIGN Prospect i ve , masked , double-controlled trial . SETTING University spine center . PARTICIPANTS One hundred fifty persons age 55 to 80 years with or without back pain and with or without magnetic resonance imaging (MRI)-demonstrated stenosis , screened for neuropathy risk , previous surgery , or cancer . INTERVENTIONS Question naires on pain and function ; ambulation testing and physical examination ; and masked electrodiagnotics and MRI . MAIN OUTCOME MEASURE Diagnostic impressions of the examining clinician , radiologist , and electrodiagnostician . RESULTS Following application of post hoc exclusion criteria and elimination of patients due to incomplete or inadequate test data , the clinical diagnosis was lumbar stenosis in 50 subjects , back pain in 44 subjects , and no pain in 32 subjects . Radiologic and clinical impression had no relation ( P = .80 vs asymptomatic , P = .99 vs back pain controls ) . Electrodiagnostic impression trended to relate to clinical impression ( P = .14 vs asymptomatic , P = .09 vs back pain ) . Retrospective application of age-related electrodiagnostic norms for paraspinal electromyographic and limb motor unit changes , established in this study , reclassified 13 of the 17 asymptomatic persons whom the electrodiagnostician thought had stenosis . The clinical impression did correspond to history and physical examination findings typically associated with spinal stenosis and to the independent impression of a neurosurgeon who examined MRI and clinical , but not to the electrodiagnostic data . CONCLUSIONS The impression obtained from an MRI scan does not determine whether lumbar stenosis is a cause of pain . Electrodiagnostic consultation may be useful , especially if age-related norms obtained in this study are applied Study Design . Prospect i ve comparative study of pain drawings with findings on lumbar spine magnetic resonance imaging . Objectives . To assess the ability of the  pain drawing  to predict the presence of nerve root compression . Summary of Background Data . Most research work has concentrated on the ability of the pain drawing to act as a screening method for psychological distress with less work directed at the influence the anatomic abnormality has on the pain drawing . Methods . One hundred thirty‐four consecutive out‐ patients attending for lumbar magnetic resonance imaging in the investigation of back and leg pain completed pain drawings and psychological testing immediately before the examination . The pain drawing was analyzed by previously reported criteria , and the magnetic resonance imaging was assessed independently for the presence of nerve compression by three radiologists . Multivariate stepwise discriminant analysis was used to identify patients with nerve compression on the basis of their pain drawing . Results . Nerve compression was predicted by numbness in the anterolateral aspect of the foot . There was considerable overlap in the appearances of the pain drawings between patients with and without nerve compression , and the pain drawing correctly classified only 58 % of patients with nerve compression . Conclusions . The pain drawing is not a good predictor of nerve compression on magnetic resonance imaging in a group of patients investigated for back and leg pain . It should be interpreted with caution and in light of the full clinical picture Background : An association has previously been reported between finger blanching and hearing difficulties , but only in workers with exposure to noise and h and transmitted vibration ( HTV ) . Aims : To explore the association in a community sample , including cases who lacked occupational exposure to noise or HTV . Method : A question naire was mailed to 12 606 subjects aged 35–64 years , chosen at r and om from the age – sex registers of 34 British general practice s. Inquiry was made about years of employment in noisy jobs , lifetime exposure to HTV , hearing difficulties and tinnitus , and lifetime history of cold induced finger blanching . Subjects were classed as having severe hearing difficulty if they used a hearing aid or found it difficult or impossible to hear conversation in a quiet room . Associations of finger blanching with hearing difficulties and tinnitus were analysed by logistic regression . Results : Among 8193 respondents were 185 who reported severe hearing difficulty and 1151 who reported finger blanching .  After adjustment for age and years of work in noisy jobs , hearing difficulty was about twice as common in men and women who reported finger blanching , including those who had never been importantly exposed to noise and in those never exposed to HTV . Conclusions : These data support an association between finger blanching and hearing loss , which is not explained by confounding occupational exposure to noise , and suggest that it may extend to causes of blanching other than vibration induced white finger . Further investigations are warranted to confirm the association and explore possible mechanisms , such as sympathetic vasoconstriction in the cochlea Study Design This was a prospect i ve study of patients ( study group ) with symptomatic disc herniations and asymptomatic volunteers ( control group ) matched for age , sex , and work-related risk factors . Objective To determine the prevalence of disc herniation in a matched group of asymptomatic volunteers and to access the diagnostic accuracy of magnetic resonance imaging , work perception , and psychosocial factors in identifying symptomatic disc herniations . Summary of Background Data Disc herniations have been reported to occur in 20–36 % of asymptomatic volunteers . A valid comparison of asymptomatic individuals and patients with disc herniations has not been performed . Methods Forty-six patients with low back pain and sciatica severe enough to require a disceclomy were compared with 46 age- , sex- , and risk factor-matched ( heavy lifting , twisting and bending , vibration , and sedentary activity ) asymptomatic voluteers .  Both groups had a complete clinical and magnetic resonance imaging examination and completed a question naire to assess differences in the psychosocial and work perception profiles . The prevalence and the severity of morphologic alterations ( disc herniation , disc degeneration , and neural compromise ) was analyzed by two independent radiologists in a blinded fashion . Differences between both groups regarding MRI findings , work perception ( occupational mental stress , intensity of concentration , job satisfaction , and job-related resignation ) and psychosocial factors ( anxiety , depression , self-control , social support , and marital status ) were compared using multivariate techniques . Stepwise discriminate analysis was used to identify the best discriminating variables within the magnetic resonance image , work perception , and psychosocial categories in terms of the diagnostic accuracy to predict group membership ( study [ pain ] or control [ no pain ] group ) . Results Matched controls had significantly more risk factors than a group of normal individuals . The present study has presented evidence that an age- , gender- , and occupational risk factors-matched group of asymptomatic patients shows a high incidence rate of disc herniations ( 76 % ) . Although significantly less than the symptomatic group incidence of 96 % , this represents a much higher prevalence rate than generally expected and reported in other studies of unmatched asymptomatic volunteers . Patients had more severe disc herniations ( disc extrusions ) than asymptomatic volunteers ( 35 % vs. 13 % ) . There was no significant differences regarding disc degeneration between both groups ( 96 % vs. 85 % ) . The only substantial morphologic difference between both groups was the presence of a neural compromise ( 83 % vs. 22 % ) , which was highly significant ( P < 0.0001 ) . There were significant differences between both groups regarding work perception ( occupational  mental stress , intensity of concentration , job satisfaction , and resignation ; P<0.027 ) and psychosocial factors ( anxiety , depression , self-control , marital status ; P<0.0001 ) . The best single predictor of a group membership was the extent of neural compromise . A combination of this factor with occupational mental stress , depression , and marital status was the best predictive model . With this model , the false-negative rate ( potential overtreatment of disc morphology ) was reduced by more than half compared with morphologic factors ( nerve root compression ) alone ( 22 % vs. 11 % ) . Conclusions . In an age- , sex- , and risk factormatched group of asymptomatic individuals , disc herniation had a substatially higher prevalence ( 76 % ) than previously reported in an unmatched group . Individuals with 
    Output:
    