#include<iostream>
using namespace std;
int main()
{
	int a;
	cin>>a;
	string b;
	cin>>b;
	for(int i=0;i<b.size();i++)
	{
		if (b[i]=='z') b[i]=b[i]-27+a;
		else b[i]+=a;
	}
	cout<<b;
	return 0;
}