#include <stdio.h>

void translate(char *buf, int n)
{
    int i, j;
    static const char alpha[] = 
	"abcdefghijklmnopqrstuvwxyz";

    for (i = 0; i < buf[i]; i++) {
	for (j = 0; alpha[j]; j++)
	  if (buf[i] == alpha[j]) {
	      j = (j + n) % (sizeof(alpha) - 1);
	      buf[i] = alpha[j];
	      break;
	  }
	if (!alpha[j]) {
	    fprintf(stderr, "Program Error: %s i=%d n=%d\n", buf, i, n);
	    exit(1);
	}
    }
}

int main(int ac, char **av)
{
    int n;
    char buf[257];

    fputs("整数> ", stdout);
    scanf(" %d", &n);
    
    fputs("変換前の文字列> ", stdout);
    scanf(" %256[a-z]", buf);
    translate(buf, n);
    printf("変換後の文字列: %s\n", buf);
    return 0;
}