#include<bits/stdc++.h>
using namespace std;
int n;
string s;
int main(){
	cin>>n;
	cin>>s;
	if(n==26){
		cout<<s;
		return 0;
	}
	for(int i=0;i<s.length();i++){
		
		if(s[i]+n>122) {s[i]='a'+('z'-n)%26;continue;}
		s[i]+=n;
		continue;
		
	}
	cout<<s;
}

第四个点过不去