#include <bits/stdc++.h>
#define l_ength size
const int inf = (1<<30);
const int mod = 1000000007;
using ll = long long;
using namespace std;

int main(){
	int n, k; cin >> n >> k;
	string str; cin >> str;
	char c_min = 'z';
	for( char c : str ) c_min = min( c, c_min );
	k = min(k, 14);
	string tmp = "";
	while( k-- ){
		tmp += str;
		reverse( str.begin(), str.end() );
		tmp += str;
		if( k > 0 ) reverse( tmp.begin(), tmp.end() );
		vector<string> candy;
		for( int i = 0; i <= n; ++i ) candy.push_back( tmp.substr(i, n) );
		sort( candy.begin(), candy.end() );
		str = candy.front();
		if( k > 0 ) reverse( str.begin(), str.end() );
		tmp = "";
	}
	cout << str << endl;
	return 0;
}