N, K = map(int, input().split())
S = input()
print("".join(c.lower() if i == K else c for i, c in enumerate(S, 1))) N, K = map(int, input().split()) N map(int, input().split()) map int input().split() ().split () input split K S = input() S input() input print("".join(c.lower() if i == K else c for i, c in enumerate(S, 1))) print "".join(c.lower() if i == K else c for i, c in enumerate(S, 1)) "".join "" join c.lower() if i == K else c i == K i K c.lower() c.lower c lower c N, K = map(int, input().split()) map(int, input().split()) N S = input() input() S K = map(int, input().split()) map(int, input().split()) K
N, K = map(int, input().split())
S = input()
print("".join(c.lower() if i == K else c for i, c in enumerate(S, 1)))