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= list(map(int, input().split()))
m=0
x, y, z=[0,0,0]
def lcm(a, b):
	return int(a*b/math.gcd(a,b))
for i in range(a,b+1):
	if i%c==0:
		x=1+math.floor((b-i)/c)
		break
for i in range(a,b+1):
	if i%d==0:
		y=1+math.floor((b-i)/d)
		break
for i in range(a,b+1):
	if i%lcm(c,d)==0:
		z=1+math.floor((b-i)/lcm(c,d))
		break
print(b-a+1-x-y+z)
# print(x, y, z)
# print(lcm(c, d))
# print(math.gcd(c,d))