import math

def fun(a,b,c,d,x):
     return a * x + b * math.sqrt(x ** 3) - c * math.exp(-x / 50.0) - d


a = 0.59912051
b = 0.64030348
c = 263.33721367
d = 387.92069617

x1 = 0.0
x2 = 100.0

check = 1

ShouldBe = 73.595368554162

while True:
    xmiddle = (x1+x2)/2.0
    fmid = fun(a,b,c,d,xmiddle)
    ans1 = fun(a,b,c,d,x1)
    ans2 = fun(a,b,c,d,x2)
    ansm = fun(a,b,c,d,xmiddle)
    check = (int)(fmid * 100000000)
    if check == 0:
        break
    if abs(ans1) < abs(ans2):
        x2 = xmiddle
    else:
        x1 = xmiddle

print(xmiddle)
print(ShouldBe)