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)

import math

a, b, c, d = (int(x) for x in input().split())
def kansu(x,y,z):
    sta = x
    end = y
    if sta%z != 0:
        sta = sta+(z-(sta%z))
    if end%z != 0:
        end = end-(end%z)
    ans = ((end-sta)/z) +1
    return ans
a1 = kansu(a,b,c)
a2 = kansu(a,b,d)
lcm = c*d/(math.gcd(c,d))
a3 = kansu(a,b,lcm)
print(int(b-a-a1-a2+a3+1))