#include<bits/stdc++.h>
using namespace std;

int main(){
    char a;
	cin >> a;
	if(isupper(a)){
		if(a=='Z'){
			cout << "A";
		}else{
    a=a+1;
			cout <<a;
		}
	}else if(islower(a)){
		if(a=='z'){
			cout << "a";
		}else{
    a=a+1;
			cout << a;
		}
	}
}