// The mook jong.cpp
#include <ios>
#include <map>
#include <set>
#include <list>
#include <cmath>
#include <ctime>
#include <deque>
#include <queue>
#include <stack>
#include <bitset>
#include <cctype>
#include <cerrno>
#include <cfloat>
#include <cstdio>
#include <cwchar>
#include <iosfwd>
#include <limits>
#include <locale>
#include <memory>
#include <string>
#include <vector>
#include <cassert>
#include <ciso646>
#include <climits>
#include <clocale>
#include <complex>
#include <csetjmp>
#include <csignal>
#include <cstdarg>
#include <cstddef>
#include <cstdlib>
#include <cstring>
#include <cwctype>
#include <fstream>
#include <iomanip>
#include <istream>
#include <numeric>
#include <ostream>
#include <sstream>
#include <utility>
#include <iostream>
#include <iterator>
#include <valarray>
#include <algorithm>
#include <exception>
#include <stdexcept>
#include <streambuf>
#include <functional>
#define LL long long
#define lson l, m, rt<<1
#define rson m+1, r, rt<<1|1
#define PI 3.1415926535897932626
#define EXIT exit(0);
#define PAUSE system("pause");
#define DEBUG puts("Here is a BUG");
#define SYNC_CLOSE ios::sync_with_stdio(false);
#define what_is(x) cout << #x << " is " << x << endl;
#define CLEAR(name, init) memset(name, init, sizeof(name));
const double eps = 1e-8;
const int MAXN = (int)1e9 + 5;
using namespace std;

LL C[66][66];

void init(void) {
    CLEAR(C, 0);
    C[0][0] = 1;
    for(int i = 1; i < 66; i++) {
        C[i][0] = C[i][i] = 1;
        for(int j = 1; j < i; j++) {
            C[i][j] = C[i-1][j-1] + C[i-1][j];
        }
    }
    for(int i = 0; i < 6; i++) {
        for(int j = 0; j <= i; j++) {
            cout << C[i][j] << " \n"[j==i];
        }
    }
}
int main(int argc, char const *argv[]) {
#ifndef ONLINE_JUDGE
    freopen("D:\\Documents\\Disk_Synchronous\\Programs\\Acm\\input.txt", "r", stdin);
#endif
    LL dp[66][66];
    CLEAR(dp, 0);
    for(int i = 1; i <= 60; i++) {
        dp[i][1] = i;
        for(int j = 2; 3*j-2 <= i; j++) {
            // what_is(i); what_is(j);
            if (i == 3*j-2) dp[i][j] = 1;
            else dp[i][j] = dp[i-1][j] + dp[i-3][j-1];
        }
    }
    /*for(int i = 1; i <= 60; i++) {
        for(int j = 1; 3*j-2 <= i; j++) {
            cout << dp[i][j] << ' ';
        }
        puts("");
    }*/
    LL res[66] = {0};
    for(int i = 1; i <= 60; i++) {
        LL tmp = 0;
        for(int j = 1; 3*j-2 <= i; j++) {
            tmp += dp[i][j];
        }
        res[i] = tmp;
        // cout << tmp << " \n"[i==60];
    }
    int n;
    while(cin >> n) {
        cout << res[n] << endl;
    }
    return 0;
}