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 Python (3.4.3) (judge verdict: Runtime Error)

from fractions import gcd
a,b,c,d = map(int,input().split())

if c == 1 or d == 1:
    print(0)
else:
    an1 = math.floor(b/c)
    an2 = math.floor((a-1)/c)
    an3 = math.floor(b/d)
    an4 = math.floor((a-1)/d) 
    gcd = round(c * d / gcd(c, d))
    an5 = math.floor(b/gcd)
    an6 = math.floor((a-1)/gcd)
    an = an1-an2 + an3-an4 -(an5-an6)
    print((b-a+1)-an)