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 fractions

A,B,C,D=map(int, input().split())

ans = 0

Cans = fractions.floor(B/C) - fractions.ceil(A/C) + 1
Dans = fractions.floor(B/D) - fractions.ceil(A/D) + 1

CD = C * D / fractions.gcd(C,D)
CDans = fractions.floor(B/CD) - fractions.ceil(A/CD) + 1

ans = (B-A+1) - (Cans + Dans - CDans)

print(ans)