#include <stdio.h>
#include <algorithm>
#include <iostream>
#include <string>
#include <vector>
#include <functional>
#include <map>
#include <iomanip>
#include <math.h> 
#include <stack>
#include <queue>
#include <bitset>
#include <cstdlib>
#include <tuple>
#include <cctype>
#include <ctype.h>

using namespace std;

int main() {
	int i, j, k;
	long n, d;

	cin >> n >> d;

	long jyo = 0, iti = 0, tugi = 0, sum = 0, cnt = 0;
	vector<long>amari;
	amari.push_back(1);
	cnt++;

	if (n - 1 == d) {
		cout << n - 1 << endl;
		getchar();
		getchar();
		return 0;
	}

	if (n == d) {
		cout << 0 << endl;
		getchar();
		getchar();
		return 0;
	}

	if (n%d == 0) {
		cout << n / d - 1 << endl;
		getchar();
		getchar();
		return 0;
	}
	else {
		cout << n / (n + 1 - (((n - 1) / d)*d + 1)) - 1 << endl;
		getchar();
		getchar();
		return 0;
	}



	while (true) {



		jyo = (n - amari[cnt-1]) / d;
		sum += jyo;
		//amari.push_back()

		iti = jyo * d + amari[cnt -1];

		tugi = d - (n - iti);

		bool flag = false;

		for (i = 0; i < cnt; i++) {
			if (amari[i] == tugi) {
				flag = true;
				break;
			}
		}

		if (flag == false) {
			amari.push_back(tugi);
			cnt++;
			sum++;
		}
		else {
			break;
		}

	}

	cout << sum << endl;




	getchar();
	getchar();
	return 0;
}