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 numpy as np
import fractions

def main():
    abcd = list(map(int, input().split(' ')))
    al = abcd[1] - abcd[0] + 1
    cc = abcd[1] // abcd[2] - (abcd[0]-1) // abcd[2]
    dd = abcd[1] // abcd[3] - (abcd[0]-1) // abcd[3]
    skbs = (abcd[2] * abcd[3]) // fractions.gcd(abcd[2], abcd[3])
    dis = cc + dd - (abcd[1] // skbs - abcd[0] // skbs)
    print(int(al - dis))

if __name__ == "__main__":
    main()