#include <iostream>
#include <cstdlib>

using namespace std;

int n;
char x;
char tab[1000000];
int a[26];
int maks;
int y, diff;

int main()
{
    
    cin >> n >> x;
    for(int i = 0; i < n; i++)
    {
        cin >> tab[i];
    }
    for(int i = 0; i < 26; i++)
    {
        a[(int)tab[i] - 65] += 1;
    }
    for(int i = 0; i < 26; i++)
    {
        if(maks < a[i])
        {
            maks = a[i];
            y = i;
        }
    }
    
    diff = abs((int)x - (y + 65));
    
    for(int i = 0; i < n; i++)
    {
        tab[i] = (int)tab[i];
        cout << (char)(tab[i] + diff);
    }
    return 0;
}