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: Wrong Answer)

import fractions,math

lis=list(map(int,input().split()))
gCD=fractions.gcd(lis[2],lis[3])
CD=int((lis[3]/gCD)*lis[2])
lis[0]=lis[0]-1
AC=lis[0]-lis[0]%lis[2]
AD=lis[0]-lis[0]%lis[3]
ACD=lis[0]-lis[0]%CD
BC=lis[1]-lis[1]%lis[2]
BD=lis[1]-lis[1]%lis[3]
BCD=lis[1]-lis[1]%CD
A=lis[0]-int(AC/lis[2])-int(AD/lis[3])+int(ACD/CD)
B=lis[1]-int(BC/lis[2])-int(BD/lis[3])+int(BCD/CD)
ans=B-A
print(ans)
#print(AC,AD,BC,BD,ACD,BCD)