#include <bits/stdc++.h>
#define PI 3.14159265359
using namespace std;
const int64_t mod = 1e9 + 7;

int main() {
	int N, K;
	string S;
	cin >> N >> K >> S;

	string s1, s2;
	s1 = S.substr(0, K - 1);
	s2 = S.substr(K - 1);
	/*cout << "s1:" << s1 << endl;
	cout << "s2:" << s2 << endl;*/

	cout << s2 + s1 << endl;
}