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)

import math
a,b,c,d=map(int,input().split())
cdg=math.gcd(c,d)
cd=c*d/cdg
ac=int(a/c)
ad=int(a/d)
acd=int(a/cd)
bc=int(b/c)
bd=int(b/d)
bcd=int(b/cd)
n=b-a+1
if a%c==0:
    cn=bc-ac+1
else:
    cn=bc-ac
if a%d==0:
    dn=bd-ad+1
else:
    dn=bd-ad
if a%(cd)==0:
    cdn=bcd-acd+1
else:
    cdn=bcd-acd
print(cd)
print(n-(cn+dn-cdn))