n,k=map(int, input("").split(' '))
assert n>=k>=1
assert 1<=n<=50

s=input('')
assert ("a","b","c" in s)

z=list((s))
z[k-1]=z[k-1].swapcase()

for i in z:
    print(i, end='')



  
 
 n,k=map(int, input("").split(' ')) n map(int, input("").split(' ')) map int input("").split(' ') ("").split ("") input "" split ' ' k assert n>=k>=1 n>=k>=1 n>=k n k 1 assert 1<=n<=50 1<=n<=50 1<=n 1 n 50 s=input('') s input('') input '' assert ("a","b","c" in s) ("a","b","c" in s) "a" "b" "c" in s "c" s z=list((s)) z list((s)) list s z[k-1]=z[k-1].swapcase() z[k-1] z k-1 k 1 z[k-1].swapcase() [k-1].swapcase [k-1] z k-1 k 1 swapcase for i in z:
    print(i, end='')



  
  i z print(i, end='') print i end='' end '' s=input('') input('') s z=list((s)) list((s)) z n,k=map(int, input("").split(' ')) map(int, input("").split(' ')) n k=map(int, input("").split(' ')) map(int, input("").split(' ')) k
n,k=map(int, input("").split(' '))
assert n>=k>=1
assert 1<=n<=50

s=input('')
assert ("a","b","c" in s)

z=list((s))
z[k-1]=z[k-1].swapcase()

for i in z:
    print(i, end='')



  
 

