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: Runtime Error)

# -*- coding: utf-8 -*-
import math
def main():
    A,B,C,D = map(int,input().split())
    E = math.lcm(C*D)
    Cc = B / C
    Dd = B / D
    Ee = B / E
    flo = A-1
    Cf = flo / C
    Df = flo / D
    Ef = flo / E
    All = B-(math.floor(Cc)+math.floor(Dd)-math.floor(Ee))
    Sub = flo-(math.floor(Cf)+math.floor(Df)-math.floor(Ef))
    print(All - Sub)
if __name__ == '__main__':
    main()