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: Accepted)

import fractions

entrada = list(map(int,input().split(" ")))

rangoMenor = entrada[0]
rangoMayor = entrada[1]
divisor1 = entrada[2]
divisor2= entrada[3]

multiplo = divisor2*divisor1// fractions.gcd(divisor1,divisor2)
cantidad = rangoMayor-rangoMenor
repetidos = rangoMayor//multiplo - rangoMenor//multiplo

if rangoMenor%divisor1==0:
	divisibles1 = rangoMayor//divisor1 +1 - rangoMenor//divisor1
else:
	divisibles1 = rangoMayor // divisor1 - rangoMenor//divisor1

divisibles2 = rangoMayor//divisor2 - rangoMenor//divisor2

resultado = cantidad -(divisibles1+divisibles2) +repetidos + 1
print(resultado)