void main() {
    int a = 5;
    a += 5;
    a += 10;
    a += 20;
    print a;

    a = 5;
    a -= 5;
    a -= -10;
    a -= 20;
    print a;

    a = 5;
    a *= 2;
    a *= 3;
    a *= 4;
    print a;

    a = 100;
    a /= 2;
    a /= 3;
    a /= 4;
    print a;

    a = 100;
    a %= 120;
    a %= 90;
    a %= 3;
    print a;
}