60分求解（玄关）

#include<bits/stdc++.h>
#define ENF 0x3f3f3f3f
#define int long long
#define endl "\n"
#define jiasu ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define jdsr for(int i=0;i<n;i++)  cin>>a[i];
#define jdsc for(int i=0;i<n;i++)  cout<<a[i]<<" ";
using namespace std;
int n;
string s; 
signed main(){
//    freopen(".in","r",stdin);
//    freopen(".out","w",stdout);
	jiasu;
	cin>>n;
	cin>>s;
	for(int i=0;i<s.length();i++){
		int t=s[i]+n;
		if(t==123){
			cout<<"a";
		}else{
			cout<<(char)t;
		}
	}
	return 0;
}