def solve():
    X, Y = map(int, input().split())

    if Y == 0:
        print(1)
        return
    elif X == 0:
        print(2)
        return
    elif X == Y:
        print(0)
        return
    elif X == -Y:
        print(3)
        return
    else:
        print(-1)

        

if __name__ == "__main__":
    solve()