#include <bits/stdc++.h>
using namespace std;
 
 
int main(){
    for(int i = 65;i <= 85;i++){
        if(i / 10 == i % 10){
            cout<<(char)i<<endl;
        }
    }
}
/**************************************************************
	Problem: 1973
	User: wangyiyang
	Language: C++
	Result: Wrong Answer
****************************************************************/