#include<stdio.h>
int main() {
	char a[100];
	int n;
	scanf("%d%s", &n,a);
	//getchar();
	//gets(a);
	for (int i = 0; a[i]!='\0'; i++) {
		if ('z'-a[i]<n%26) {
			a[i] = 'a' + (n % 26) - ('z' - a[i])-1;
		}
		else a[i] = a[i] + n%26;
	}
	for (int i = 0; a[i] != '\0'; i++)putchar(a[i]);
	//puts(a);
}