#include <iostream>
#include <cstdio>
using namespace std;

int main(){
	int n;
	cin>>n;
	int r=n%123;
	if(r>=97&&r<=122){
		cout<<char(r);
	}else{
		r=n%91;
		if(r>=65&&r<=90){
			cout<<char(r);
		}else{
			cout<<'*';
		}
	}
	return 0;
}