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)

import fractions
a, b, c, d = map(int, input().split())
e = int(c*d/fractions.gcd(c, d))
if a%c != 0:
	fc = (int(a/c)+1)*c
else:
	fc = (int(a/c))*c
if b%c != 0:
	tc = (int(b/c))*c
else:
	tc = (int(b/c))*c
sc = int((tc - fc)/c)+1
if fc > tc:
  sc = 0

if a%d != 0:
	fd = (int(a/d)+1)*d
else:
	fd = (int(a/d))*d
if b%d != 0:
	td = (int(b/d))*d
else:
	td = (int(b/d))*d
sd = int((td - fd)/d)+1
if sd > td:
  sd = 0

if a%e != 0:
	fe = (int(a/e)+1)*e
else:
	fe = (int(a/e))*e
if b%e != 0:
	te = (int(b/e))*e
else:
	te = (int(b/e))*e
se = int((te - fe)/e)+1
if fe > te:
  se = 0

ss = (b-a+1)-(sc+sd-se)
print(ss)