import java.util.*; import java.io.*; @SuppressWarnings("unused") public class Main { private static void solve() { long h = nl(); long a = nl(); long ret = 0; long cnt = 1; while (h > 0) { h /= a; ret += cnt; cnt *= 2; } System.out.println(ret); } public static void main(String[] args) { new Thread(null, new Runnable() { @Override public void run() { solve(); out.flush(); } }, "", 64000000).start(); } private static PrintWriter out = new PrintWriter(System.out); private static StringTokenizer tokenizer = null; private static BufferedReader reader = new BufferedReader(new InputStreamReader(System.in), 32768); public static String next() { while (tokenizer == null || !tokenizer.hasMoreTokens()) { try { tokenizer = new java.util.StringTokenizer(reader.readLine()); } catch (Exception e) { throw new RuntimeException(e); } } return tokenizer.nextToken(); } private static double nd() { return Double.parseDouble(next()); } private static long nl() { return Long.parseLong(next()); } private static int[] na(int n) { int[] a = new int[n]; for (int i = 0; i < n; i++) a[i] = ni(); return a; } private static char[] ns() { return next().toCharArray(); } private static long[] nal(int n) { long[] a = new long[n]; for (int i = 0; i < n; i++) a[i] = nl(); return a; } private static int[][] ntable(int n, int m) { int[][] table = new int[n][m]; for (int i = 0; i < n; i++) { for (int j = 0; j < m; j++) { table[i][j] = ni(); } } return table; } private static int[][] nlist(int n, int m) { int[][] table = new int[m][n]; for (int i = 0; i < n; i++) { for (int j = 0; j < m; j++) { table[j][i] = ni(); } } return table; } private static int ni() { return Integer.parseInt(next()); } }