import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

a,b,c,d,e,f = map(int,read().split())

x,y,z = sorted([d+e,d+f,e+f])

a,b,c = sorted([a,b,c])
answer = 2 * (a*z+b*y+c*x)

print(answer)