ELEVTRBL  Elevator Trouble
You are on your way to your first job interview as a program tester, and you are already late. The interview is in a skyscraper and you are currently in floor s, where you see an elevator. Upon entering the elevator, you learn that it has only two buttons, marked "UP u" and "DOWN d". You conclude that the UPbutton takes the elevator u floors up (if there aren't enough floors, pressing the UPbutton does nothing, or at least so you assume), whereas the DOWNbutton takes you d stories down (or none if there aren't enough). Knowing that the interview is at floor g, and that there are only f floors in the building, you quickly decide to write a program that gives you the amount of button pushes you need to perform. If you simply cannot reach the correct floor, your program halts with the message "use the stairs".
Given input f, s, g, u and d (floors, start, goal, up, down), find the shortest sequence of button presses you must press in order to get from s to g, given a building of floors, or output "use the stairs" if you cannot get from s to g by the given elevator.
Input
The input will consist of one line, namely f s g u d, where 1 <= s, g <= f <= 1000000 and 0 <= u, d <= 1000000. The floors are oneindexed, i.e. if there are 10 stories, s and g be in [1; 10].
Output
You must reply with the minimum numbers of pushes you must make in order to get from s to g, or output "use the stairs" if it is impossible given the conguration of the elevator.
Example
Input: 10 1 10 2 1 Output: 6
Input: 100 2 1 1 0 Output: use the stairs
hide comments
veerendrasd_9:
20190723 17:54:33
remember to define a tree such that a property can do the work, in such type of problems.


prudhvi_495:
20190620 12:03:02
It's a simple bfs problem just print the level of g in the graph. 

cenation007:
20190603 07:28:15
bfs is love 

dkkv0000:
20190525 07:15:59
good bfs 

dmorgans:
20190412 20:36:21
ac in 2nd attempt


dashubaba:
20190412 18:56:21
Dear admin, can you give me some clue where I got the WA. 

mynk322:
20190312 20:03:07
AC in 2nd go!


vickyand_27:
20190131 17:04:41
my 14th bfs is cool 

harshraj22aug:
20181219 17:31:40
what is the problem if we mark the floor as reached when we pop it out of the queue instead of marking it while pushing in ?


surajkumar_cse:
20181214 11:45:57
TLE

Added by:  Krzysztof Lewko 
Date:  20111006 
Time limit:  1s 
Source limit:  50000B 
Memory limit:  1536MB 
Cluster:  Cube (Intel G860) 
Languages:  All except: ASM64 
Resource:  Nordic programming contest 