#include<iostream>
#include<string>

using namespace std;

int main() {

	string initialString = "ABCDEFGHIJKLMNOPQR";
	cout<<initialString<<endl;
	for(int i = 0; i < 9; i++) {
		initialString = string(1, 'B' + i) + initialString.substr(0, initialString.length() - 1);
		cout<<initialString<<endl;
	}
	return 0;
}