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

for i in range(n - k + 1):
    # Reverse the substring from i to i + k - 1
    left = i
    right = i + k - 1
    while left < right:
        s[left], s[right] = s[right], s[left]
        left += 1
        right -= 1

print(''.join(s))