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)

def gcd(x, y):
	if (x > y) :
		x , y = y , x
	r = x % y
	while(r != 0) :
		x = y;
		y = r;
		r = x % y;
	
	return y
def lcm(x, y):
    return (x * y) // gcd(x, y)

str = input()
A = int(str.split()[0])
B = int(str.split()[1])
C = int(str.split()[2])
D = int(str.split()[3])

aKc = int(A / C)
bKc = int(B / C)
aKd = int(A / D)
bKd = int(B / D)

lcm = lcm(C, D)
aKcd = int(A / lcm)
bKcd = int(B / lcm)

sB = B - bKc - bKd + bKcd
sA = A - 1 - aKc - aKd + aKcd

print("{}".format(sB- sA))