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
import math

A,B,C,D = map(int,input().split())

U = B - A + 1

nA = ( math.floor(B / C) ) - (math.ceil(A / C)) +1

nB = ( math.floor(B / D) ) - (math.ceil(A / D)) +1

saisyoukoubaisuu = C * D / fractions.gcd(C, D)

saisyoukoubaisuu = int(saisyoukoubaisuu)

nAB =  (math.floor(B/saisyoukoubaisuu)) - (math.ceil(A/saisyoukoubaisuu)) + 1

print( U -(nA + nB - nAB) )