k,s=open(0)
k=int(k[2:])
print(s[:k-1]+s[k-1].lower()+s[k:]) k,s=open(0) k open(0) open 0 s k=int(k[2:]) k int(k[2:]) int k[2:] k 2: 2 print(s[:k-1]+s[k-1].lower()+s[k:]) print s[:k-1]+s[k-1].lower()+s[k:] s[:k-1]+s[k-1].lower() s[:k-1] s :k-1 k-1 k 1 s[k-1].lower() [k-1].lower [k-1] s k-1 k 1 lower s[k:] s k: k k,s=open(0) open(0) k s=open(0) open(0) s k=int(k[2:]) int(k[2:]) k
k,s=open(0)
k=int(k[2:])
print(s[:k-1]+s[k-1].lower()+s[k:])