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 PyPy3 (2.4.0) (judge verdict: Accepted)

import fractions
a,b,c,d=map(int,input().split())
ans=0
ca=[]
da=[]
cda=[]
minimunc=-(-a//c)
minimund=-(-a//d)
minimuncd=-(-a//((c*d)//fractions.gcd(c,d)))
maximunc=b//c
maximund=b//d
maximuncd=b//((c*d)//fractions.gcd(c,d))
totalc=maximunc-minimunc+1
totald=maximund-minimund+1
totalcd=maximuncd-minimuncd+1

print((b-a+1)-(totalc+totald-totalcd))