You are given a trapezoid. The lengths of its upper base, lower base, and height are a, b, and h, respectively.    An example of a trapezoid  Find the area of this trapezoid.

def main():
    a = int(input())
    b = int(input())
    h = int(input())
    print((a + b) * h / 2)
    

if __name__ == "__main__":
    main()


def main():
    a = int(input())
    b = int(input())
    h = int(input())
    print((a + b) * h // 2)


if __name__ == "__main__":
    main()
