#include <iostream>
using namespace std;


int main() {
	
	int count = 0;
	for (int i = 97; i <= 122; i++) {
		for (int j = 97; j <= 122; j++) {
			cout << (char)i << 'r' << (char)j << endl;
			count += 1;
		}
	}
	
	cout << count << endl;
	return 0;
}