/*
 * Caesar cipher
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define N 128

int main(int argc, char *argv[])
{
    char buf[N+1], c;
    int key, i;

    key = atoi(argv[1]);
    strncpy(buf, argv[2], N);

    for (i = 0; i < strlen(buf); i++)
    {
        c = buf[i];
        c = 'a' + (c - 'a' + key)%26;
        printf("%c", c);
    }
    printf("\n");

    return 0;
}