include<stdio.h>

include<string.h>

int main()

int n, i; 
    char s[100];
    scanf("%d", &n);
    getchar(); 
    gets(s);
    int len = strlen(s);
    for(i = 0;i < len;i++)
    {
        s[i] = (s[i] - 'a' + n % 26) % 26 + 'a';
        printf("%c", s[i]);
    }
    return 0;
}