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: Wrong Answer)

A,B,C,D=map(int,input().split())

def gcd(a,b):
    while b!=0:
        a,b=b,a%b
    return a

def lcm(a,b):
    return a*b/gcd(a,b)

if A%C == 0:
    AC = int(A/C) - 1
else:
    AC = int(A/C)
if A%D == 0:
    AD = int(A/D) - 1
else:
    AD = int(A/D)
    
lcmCD = lcm(C,D)
if A%(lcmCD) == 0:
    ACD = int(A/(lcmCD)) - 1
else:
    ACD = int(A/(lcmCD))
    
ans = (B - A + 1) - (int(B/C) - AC + int(B/D) - AD - int(B/lcmCD) + ACD)

print(ans)