Problem:
Score : 300 points

Problem Statement

You are given four integers A, B, C, and D. Find the number of integers between A and B (inclusive) that can be evenly divided by neither C nor D.

Constraints

1\leq A\leq B\leq 10^{18}

1\leq C,D\leq 10^9

All values in input are integers.

Input

Input is given from Standard Input in the following format:

A B C D

Output

Print the number of integers between A and B (inclusive) that can be evenly divided by neither C nor D.

Sample Input 1

4 9 2 3

Sample Output 1

2

5 and 7 satisfy the condition.

Sample Input 2

10 40 6 8

Sample Output 2

23

Sample Input 3

314159265358979323 846264338327950288 419716939 937510582

Sample Output 3

532105071133627368

Solution in Python (3.4.3) (judge verdict: Runtime Error)

import fractions
a,b,c,d=map(int,input().split())
g=fractions.gcd(c,d)
l=int(c*d/g)
x=b-a
ac=a/c
acc=a//c
bc=b/c
bcc=b//c
ad=a/d
add=a//d
bd=b/d
bdd=b//d
al=a/l
al1=a/ll
bl=b/l
bl1=b/ll
if ac==int(ac) or bc==int(bc):
    cans=bcc-acc+1
else:
    cans=bcc-acc
if ad==int(ad) or  bd==int(bd):
    dans=bdd-add+1
else:
    dans=bdd-add
if al==int(al) or  bl==int(bl):
    lans=bl1-al1+1
else:
    lans=bl1-al1   

re=int(x+1-(cans+dans-lans))
print(re)