Author:  A. Klenin, I. Tuphanov  Time limit:  1 sec  
Input file:  input.txt  Memory limit:  256 Mb  
Output file:  output.txt 
Young builder Vasya was requested to hang wallpaper on the wall. The wall is a rectangle of W meters wide and H meters high, with a rectangular door of w meters wide and h meters high, located at the left side of the wall. Wallpaper is packaged into rolls. Each roll is 1 meter wide and D meters long, which Vasya may have to cut into shorter stripes of equal width.
Vasya has a high standard for work quality, so he must:
Your program must calculate the minimum number of wallpaper rolls required to complete the task.
In the example below it is optimal to cut rolls into stripes of lengths 3+2+1. If different rolls could be cut into different stripe sequences, then a better solution would be to cut one roll into lengths 3+3 and another one into 2+2+2.
The input file contains integers W H w h D. It is guaranteed that the answer exists for given input.
Output must contain a single integer — the minimum number of rolls.
1 ≤ W, H, w, h ≤ 10^{9}; 1 ≤ D ≤ 2 × 10^{9};
h ≤ H; w ≤ W;
No.  Input file (input.txt ) 
Output file (output.txt ) 

1 

