#include <iostream>
#include <cstdlib>
#include <ctime>

using namespace std;

int main() {
    srand(time(nullptr));
    const int width = 640;
    const int height = 480;
    cout << "P3\n" << width << " " << height << "\n255\n";
    for (int y = 0; y < height; ++y) {
        for (int x = 0; x < width; ++x) {
            int gray = rand() % 256;
            cout << gray << " " << gray << " " << gray << " ";
        }
        cout << "\n";
    }
    return 0;
}