代码如下：

#include <bits/stdc++.h>
using namespace std;
int main(){
	int n;
	char s;
	scanf("%d\n",&n);
	while(1){
		s = getchar();
		if (s=='\n') break;
		else putchar((s-'a'+n)%26+'a');
	}
	return 0;
}