#include<iostream>
#include<ctime>

using namespace std;

int main() {
    int a, b;
    srand(time(0));
    while (1) {
        a = rand() % 16;
        b = rand() % 16;
        while (1) {
            int c;
            cout << hex << uppercase << a << " + " << b << " = ";
            cin >> hex >> c;

            if (c == a + b) {
                cout << "Yes!" << endl;
                break;
            }

            else if (c != a + b) {
                cout << "No!" << endl;
                continue;
            }

        }

    }

}