def S(q,m,n):
k=q+m+n
p=k/2
S=(p*(p-q)*(p-m)*(p-n))**(1/2)
return S

a=eval(input())
b=eval(input())
c=eval(input())
r=eval(input())
s=eval(input())
t=eval(input())

S2=S(a,b,c)+S(a,r,s)+S(b,r,t)+S(c,s,t)
print(S2)

a = float(input())
b = float(input())
c = float(input())
r = float(input())
s = float(input())
t = float(input())

def sum (m,n,o):
p = (m + n + o)/2
s = (p*(p-m)*(p-n)*(p-o))**0.5
return s

n = sum(a,b,c)+sum(r,b,t)+sum(a,r,s)+sum(s,t,c)
print('%.2f'%n)

题目有改动