N, K = map(int, input().split())
S = input()
ans = []
for i in range(K-1, N):
    ans.append(S[i])
if (N-K+1)%2==0:
    for i in range(K-1):
        ans.append(S[i])
else:
    for i in range(K-2, -1, -1):
        ans.append(S[i])
print("".join(ans))