#include <bits/stdc++.h>
using namespace std;
#define modulo 998244353
#define mod(mod_x) ((((long long)mod_x+modulo))%modulo)
#define Inf 100000000


int main(){
	
	int N,K;
	cin>>N>>K;
	string S;
	cin>>S;
	char min_c = '{';
	for(int i=0;i<S.size();i++){
		min_c = min(min_c,S[i]);
	}
	
	string k(N,min_c);
	
	for(int i=0;i<K;i++){
		string T = S;
		reverse(S.begin(),S.end());
		T += S;
		
		string s = "{";
		for(int j=0;j<=N;j++){
			s = min(s,T.substr(j,N));
		}
		
		if(i!=K-1)reverse(s.begin(),s.end());
		S = s;
		if(S==k)break;
		
	}
	
	
	
	
	cout<<S<<endl;
		
	
	return 0;
}
