import java.util.Scanner;
public class Main{
	public static void main(String... args){
		Scanner scan = new Scanner(System.in);
		long n = scan.nextLong();
		int a = scan.nextInt();
		int b = scan.nextInt();
		int c = scan.nextInt();
		System.out.println((n/a+n/b) - n/c);
	}
}