#include <iostream>
#include <string>
#include <vector>
#include <numeric>

using namespace std;
int main() 
{
	int N,K;
	cin >> N;
	cin >> K;
	string S;
	cin >> S;
	std::vector<int> v(S.length());
	iota(v.begin(), v.end(), 0);
	for (int i = 1; i <= N - K + 1; ++i)
	{
		int m = i - 1;
		int n = i + K - 2;
		while (m != n && m < n)
		{
			int c = v[m];
			v[m] = v[n];
			v[n] = c;
			++m;
			--n;
		}
	}
	string R;
	for (auto itr = v.begin(); itr != v.end(); ++itr)
		R += S[*itr];
	cout << R << endl;
	return 0;
}