import math

def func(x) -> float:
    return math.pow(x, 2) * math.sqrt(36 - math.pow(x, 2))

def left(a, b, h) -> float:
    summ = 0
    xk = a
    while xk < b:
        summ = summ + func(xk)
        xk = xk + h
    return h * summ

def num(a, b, h) -> float:
    return abs((a - b)/h)

if __name__ == "__main__":
    a = 1
    b = 5
    h = 1
    print(left(a, b, h))