#include <vector>
#include <iostream>
using namespace std;
int main() {
	cin.tie(0);
	ios_base::sync_with_stdio(false);
	int N, K; string S;
	cin >> N >> K >> S;
	for (int i = 0; i < N; ++i) {
		cout << S[i <= N - K ? i + K - 1 : ((N - K) % 2 == 0 ? N - i - 1 : K - (N - i) - 1)];
	}
	cout << endl;
	return 0;
}