import math 
import sys 
sys.stdin = open('input.txt', 'r') 
sys.stdout = open('output.txt', 'w') 
 
(a, b, c) = [int(s) for s in input().split()] 
(h, l) = [int(s) for s in input().split()] 
 
s=2*a*c+2*b*c+a*b 
rulon=h*l/1000000 
s=s*0.85 
s=s*1.1 
s=s/rulon 
s=math.ceil(s) 
print(s)