from math import sqrt
def f(x, y, z):
return round( (x + y + sqrt((x-y)**2 + 4*z**2)) / 2, 2)
print(f(1, 2, 3))
from math import *
x = int(input())
y = int(input())
z = int(input())
result = (x + y + sqrt((x-y)**2 + 4*z**2))/2
result = round(result, 2)
print(result)
from math import sqrt
def f(x, y, z):
return round( (x + y + sqrt((x-y)**2 + 4*z**2)) / 2, 2)
print(f(1, 2, 3))
from math import *
x = int(input())
y = int(input())
z = int(input())
result = (x + y + sqrt((x-y)**2 + 4*z**2))/2
result = round(result, 2)
print(result)