Author:  A. Usmanov, L. Verkhovtsev. Translation: A. Logutova.  Time limit:  1 sec  
Input file:  Standard input  Memory limit:  256 Mb  
Output file:  Standard output 
Leonid is an astronaut. His spaceship crashed on far unknown planet, full of natural resources. Leonid couldn't repair his spaceship, therefore he stayed on the planet. Many years later he achieved fantastic progress in planet exploration — he built an ore mining and processing mill.
The mill works in several stages:
1. N drills mine the ore. The speed of one drill is U_{N} kilograms per hour;
2. The ore gets to melting furnaces. The speed of one furnace is U_{K} kilograms per hour;
3. After furnaces, plates get to M machinetools. The speed of one machinetool is U_{M} kilograms per hour.
Leonid's mill pollutes the planet. This pollution disturbed inhabitants of the planet. Fictional arthropods have broken all furnaces.
Leonid is planning to build new furnaces and to renew manufacture. But at first he wants to calculate an optimal number of furnaces. We will call "surplus" the total quantity of the ore and plates, which is waiting for the processing. The number of furnaces is optimal if the surplus is minimal for the fixed period of time.
Help Leonid to calculate optimal number of furnaces. Obviously, Leonid wants to renew manufacture as fast as possible. Therefore among all possible answers, you should choose the minimal one.
The first line contains two integers N and M — the number of drills and machinetools respectively.
The second line contains three integers U_{N}, U_{K} and U_{M} — the speeds of one drill, one furnace and one machinetool respectively.
Print an integer — optimal number of furnaces.
If there are several possible answers, choose the minimal one.
1 ≤ N, M, U_{N}, U_{K}, U_{M} ≤ 10^{9}
Let's consider first test. Let's fix the period of time — T = 10 hours. Amount of produced resources is shown in the table.
Number of furnaces  Mined ore, kg  Melted ore, kg  Surplus ore, kg  Processed plates, kg  Surplus plates, kg  Surplus ore and plates, kg 

1  100  30  70  30  0  70 + 0 
2  60  40  60  0  40 + 0  
3  90  10  70  20  10 + 20  
4  100  0  70  30  0 + 30 
Surpluses are equal for three and four furnaces, which means that three furnaces is enough.
No.  Standard input  Standard output 

1 


2 


3 

