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 fractions

a,b,c,d = map(int,input().split())
#print(a,b,c,d)
gcd = int(fractions.gcd(c,d))
lcm = int(c*d / gcd)
#print(gcd,lcm)


c_div1 = int((a-1) / c)
c_div2 = int(b / c)
d_div1 = int((a-1) / d) 
d_div2 = int(b / d)
lcm_div1 = int((a-1) / lcm)
lcm_div2 = int(b / lcm)

ans = int(c_div2 - c_div1) + int(d_div2 - d_div1) - int(lcm_div2 - lcm_div1)
#print(c_div1,c_div2,d_div1,d_div2,lcm_div1,lcm_div2)
print(int(b - a - ans + 1))