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 Julia (0.5.0) (judge verdict: Wrong Answer)

parseInt(x) = parse(Int128,x)

function main()
  (A,B,C,D) = map(parseInt, split(readline()))
  if B/C < 1 
    dc = 0
  else
    if A/C < 1
      dc = Int(floor(B/C))
    else
      dc = Int(floor(B/C))-Int(ceil(A/C))+1
    end
  end
  if B/D < 1 
    dd = 0
  else
    if A/D < 1
      dd = Int(floor(B/D))
    else
      dd = Int(floor(B/D))-Int(ceil(A/D))+1
    end
  end
  E = lcm(C,D)
  if B/E < 1 
    de = 0
  else
    if A/E < 1
      de = Int(floor(B/E))
    else
      de = Int(floor(B/E))-Int(ceil(A/E))+1
    end
  end
  k = (B-A+1)-(dc+dd-de)
  println(k)
end

main()