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 Go (1.6) (judge verdict: Wrong Answer)

package main

import "fmt"
import "bufio"
import "os"
import "strconv"

//   1 2 3 4 5 6 7 8 9
// 2 . 2 . 2 . 2 . 2 .
// 3 . . 3 . . 3 . . 3
var _sw = bufio.NewScanner(os.Stdin)

func main() {
	lower := NextInt()
	upper := NextInt()
	n := NextInt()
	m := NextInt()

	lower--

	ans := ((upper / n) - (lower / n)) + ((upper / m) - (lower / m)) - ((upper / LCM(n, m)) - (lower / LCM(n, m)))
	fmt.Println(ans, upper-lower-ans)
}

func init() {
	_sw.Split(bufio.ScanWords)
}

func NextInt() int {
	if _sw.Scan() == false {
		panic(_sw.Err())
	}
	i, e := strconv.Atoi(_sw.Text())
	if e != nil {
		panic(e)
	}
	return i
}

func NextString() string {
	if _sw.Scan() == false {
		panic(_sw.Err())
	}
	return _sw.Text()
}

func Max(x, y int) int {
	if x > y {
		return x
	}
	return y
}

func Min(x, y int) int {
	if x > y {
		return y
	}
	return x
}

func GCD(a, b int) int {
	for b != 0 {
		t := b
		b = a % b
		a = t
	}
	return a
}

func LCM(a, b int, integers ...int) int {
	result := a * b / GCD(a, b)

	for i := 0; i < len(integers); i++ {
		result = LCM(result, integers[i])
	}

	return result
}