Triangle Circulation

// Operating GCD(1/2)
long GCD = GCD(Math.max(A, B), Math.min(A, B));

// External Module(1/2)
private static long GCD(long B, long S) {
    long r = B % S;
    while (r != 0) {
        r = B%S;
        B = S;
        S = r;
    }
    return Math.abs(B);
}