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

int sum;
int main() {
	char a = getchar();
	char b = getchar();
	sum = a + b - 'A' - 'A';
	if(sum <= 25)
		cout << char(sum + 'A');
	else
		cout << 'B' << char(sum + 'A' - 26);
	return 0;
}