uniform half4 colorRed, colorGreen;

half4 main() {
    bool ok = true;

    int a = 1;
    a = a + a; // 2
    a += a;    // 4
    a = a + a; // 8
    a += a;    // 16
    a = a + a; // 32
    ok = ok && (a == 32);

    int b = 10;
    b = b - 2; // 8
    b -= 2;    // 6
    b = b - 1; // 5
    b -= 3;    // 2
    ok = ok && (b == 2);

    int c = 2;
    c = c * c; // 4
    c *= c;    // 16
    c = c * 4; // 64
    c *= 2;    // 128
    ok = ok && (c == 128);

    int d = 256;
    d = d / 2; // 128
    d /= 2;    // 64
    d = d / 4; // 16
    d /= 4;    // 4
    ok = ok && (d == 4);

    return ok ? colorGreen : colorRed;
}