n,k=[int(x) for x in input().rstrip().split()]
s=[i for i in input()]
ans=""
s[k-1]=s[k-1].lower()
for i in s:
  ans+=i
print(ans) int(x) for x in input().rstrip().split() for x in input().rstrip().split() x input().rstrip().split() ().rstrip().split ().rstrip() ().rstrip () input rstrip split for x in input().rstrip().split() int(x) int x n,k=[int(x) for x in input().rstrip().split()] n [int(x) for x in input().rstrip().split()] k i for i in input() for i in input() i input() input for i in input() i s=[i for i in input()] s [i for i in input()] ans="" ans "" s[k-1]=s[k-1].lower() s[k-1] s k-1 k 1 s[k-1].lower() [k-1].lower [k-1] s k-1 k 1 lower for i in s:
  ans+=i i s ans+=i ans i print(ans) print ans ans+=i i ans n,k=[int(x) for x in input().rstrip().split()] [int(x) for x in input().rstrip().split()] n k=[int(x) for x in input().rstrip().split()] [int(x) for x in input().rstrip().split()] k ans="" "" ans s=[i for i in input()] [i for i in input()] s
n,k=[int(x) for x in input().rstrip().split()]
s=[i for i in input()]
ans=""
s[k-1]=s[k-1].lower()
for i in s:
  ans+=i
print(ans)