#include<iostream>
#include<string>
#include<string.h>
#include<algorithm>
#include<stdio.h>
#include<cmath>
#include<vector>
#include<utility>
#include<stack>
#include<queue>
#include<list>
#include<bitset>
#include<functional>

#define FOR(i, a, b) for(int i=(a);i<=(b);i++)
#define RFOR(i, a, b) for(int i=(a);i>=(b);i--)
#define MOD 1000000007
#define INF 1000000000

using namespace std;

int main(void) {
	long long int n, k;
	long long int p, q;

	cin >> n >> k;
	p = n / (k + 1) + 1;
	q = n - k + 2;
	if (p < 0) {
		p = 10e18;
	}
	if (q < 0) {
		q = 10e18;
	}
	cout << min(p,q) << endl;

	return 0;
}