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

print(lis)

AmodC=lis[0]%lis[2]
if AmodC==0:
    AC=lis[0]
else:
    AC=lis[0]+(lis[2]-AmodC)
AmodD=lis[0]%lis[3]
if AmodD==0:
    AD=lis[0]
else:
    AD=lis[0]+(lis[3]-AmodD)
AmodCD=lis[0]%CD
if AmodCD==0:
    ACD=lis[0]
else:
    ACD=lis[0]+(CD-AmodCD)

BmodC=lis[1]%lis[2]
if BmodC==0:
    BC=lis[1]
else:
    BC=lis[1]-BmodC
BmodD=lis[1]%lis[3]
if BmodD==0:
    BD=lis[1]
else:
    BD=lis[1]-BmodD
BmodCD=lis[1]%CD
if BmodCD==0:
    BCD=lis[1]
else:
    BCD=lis[1]-BmodCD



ans=int((lis[1]-(BC/lis[2]+BD/lis[3]-BCD/CD))-(lis[0]-(AC/lis[2]+AD/lis[3]-ACD/CD)))

print(ans)
#print(AC,AD,BC,BD,ACD,BCD)