#include<bits/stdc++.h>

using namespace std;

int main(){

	int n;
	scanf("%d",&n);
	string m;
	cin>>m;
	for(int i=1;i<=m.length();i++){
		if(m[i]+n>"z"){
			m[i]-=26;
			m[i]+=n;
		} 
		else{
			m[i]+=n;
		}
		cout<<m[i];
	}
	return 0;
} 

为啥显示 ISO C++ forbids comparison between pointer and integer [-fpermissive]？