Baekjoon #1229

import java.util.*;
import java.io.*;

public class Main {
    public static void main(String[] args) {
        FastReader rd = new FastReader();
        int N = rd.nextInt();

        List<Integer> list = new ArrayList<>();

        // 육각수 만들기
        list.add(1);
        int sum = 5;
        while (list.get(list.size() - 1) + sum <= N) {
            list.add(list.get(list.size() - 1) + sum);
            sum += 4;
        }


        int dp[] = new int[N + 1];
        for (int i = 1; i <= N; i++) {
            dp[i] = 6;
            for (int s : list) {
                if (s > i) break;
                dp[i] = Math.min(dp[i], dp[i - s] + 1);
            }
        }

        System.out.println(dp[N]);
    }

    static class FastReader {
        BufferedReader br;
        StringTokenizer st;

        public FastReader() {
            br = new BufferedReader(new InputStreamReader(System.in));
        }

        String next() {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }

        int nextInt() {
            return Integer.parseInt(next());
        }

        long nextLong() {
            return Long.parseLong(next());
        }

        double nextDouble() {
            return Double.parseDouble(next());
        }

        String nextLine() {
            String str = "";
            try {
                str = br.readLine();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return str;
        }
    }
}