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)

A, B, C, D = map(int, input().split())
count = 0
area = B-A+1
count += int(area/C)
if (B%C + A%C) >=C:
    count+=1
count += int(area/D)
if (B%D + A%D) >=D:
    count+=1
E = C*D
count -= int(area/E)
if (B%E + A%E) >=E:
    count-=1

print(area-count)