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: Wrong Answer)

import sys
from io import StringIO
import unittest
import fractions
import math


#from numba import jit
def lcm(x, y):
    return (x * y) // fractions.gcd(x, y)


def search(x, A, B):
    x_min = 0
    x_max = 0
    for i in range(1000000000):
        if (x * i > A):
            x_min = i
            break
    for i in range(1000000000):
        if (x * i > B):
            x_max = i
            break
    return x_max - x_min


def resolve():
    A, B, C, D = map(int, input().split())
    size = B - A + 1

    C_warikire = search(C, A, B)
    D_warikire = search(D, A, B)
    C_and_D_warikire = search(lcm(C, D), A, B)
    print(size - C_warikire - D_warikire + C_and_D_warikire)
    
resolve()