n, k = map(int, input().split())
s = input()

part1 = s[:k - 1]
part2 = s[k - 1].lower()
part3 = s[k:]

# print(f'{part1}{part2}{part3}')
print('{part1}{part2}{part3}'.format(part1=part1, part2=part2, part3=part3)) n, k = map(int, input().split()) n map(int, input().split()) map int input().split() ().split () input split k s = input() s input() input part1 = s[:k - 1] part1 s[:k - 1] s :k - 1 k - 1 k 1 part2 = s[k - 1].lower() part2 s[k - 1].lower() [k - 1].lower [k - 1] s k - 1 k 1 lower part3 = s[k:] part3 s[k:] s k: k print('{part1}{part2}{part3}'.format(part1=part1, part2=part2, part3=part3)) print '{part1}{part2}{part3}'.format(part1=part1, part2=part2, part3=part3) '{part1}{part2}{part3}'.format '{part1}{part2}{part3}' format part1=part1 part1 part1 part2=part2 part2 part2 part3=part3 part3 part3 s = input() input() s part1 = s[:k - 1] s[:k - 1] part1 n, k = map(int, input().split()) map(int, input().split()) n k = map(int, input().split()) map(int, input().split()) k part2 = s[k - 1].lower() s[k - 1].lower() part2 part3 = s[k:] s[k:] part3
n, k = map(int, input().split())
s = input()

part1 = s[:k - 1]
part2 = s[k - 1].lower()
part3 = s[k:]

# print(f'{part1}{part2}{part3}')
print('{part1}{part2}{part3}'.format(part1=part1, part2=part2, part3=part3))
