import java.util.Scanner;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;

class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        long n = in.nextLong();
        long k = in.nextLong();

        if(k == 1) {
            System.out.println(n / 2 + 1);
        } else {
            System.out.println(n / (k+1) + 1);
        }

        in.close();
    }
}