#include <algorithm>
#include <bitset>
#include <cassert>
#include <cctype>
#include <clocale>
#include <cmath>
#include <cstdlib>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <set>
#include <sstream>
#include <string>
#include <tuple>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>

using namespace std;

#define IOS ios::sync_with_stdio(false); cin.tie(0);
#define FOR(i, s, n) for(int i = (s), i##_len=(n); i < i##_len; ++i)
#define FORS(i, s, n) for(int i = (s), i##_len=(n); i <= i##_len; ++i)
#define VFOR(i, s, n) for(int i = (s); i < (n); ++i)
#define VFORS(i, s, n) for(int i = (s); i <= (n); ++i)
#define REP(i, n) FOR(i, 0, n)
#define REPS(i, n) FORS(i, 0, n)
#define VREP(i, n) VFOR(i, 0, n)
#define VREPS(i, n) VFORS(i, 0, n)
#define RFOR(i, s, n) for(int i = (s), i##_len=(n); i >= i##_len; --i)
#define RFORS(i, s, n) for(int i = (s), i##_len=(n); i > i##_len; --i)
#define RREP(i, n) RFOR(i, n, 0)
#define RREPS(i, n) RFORS(i, n, 0)
#define ALL(v) (v).begin(), (v).end()
#define SORT(v) sort(ALL(v))
#define RSORT(v) sort(ALL(v), greater<decltype(v[0])>())
#define SZ(x) ((int)(x).size())
#define PB push_back
#define MP make_pair
#define MT make_tuple
#define BIT(n) (1LL<<(n))
#define UNIQUE(v) v.erase(unique(ALL(v)), v.end())

using ll = long long;
using PII = pair<int, int>;
using VI = vector<int>;
using VD = vector<double>;
using VLL = vector<ll>;
using VS = vector<string>;
using VC = vector<char>;
using VB = vector<bool>;

const int MOD = 1000000007;
const int INF = 1000000000;

template<class T>
bool chmax(T &a, const T &b){
    if(a < b){
        a = b; return true;
    }
    return false;
}
template<class T>
bool chmin(T &a, const T &b){
    if(b < a){
        a = b; return true;
    }
    return false;
}



int main(){
    int n; cin >> n;
    //dp[i][j] = i段目へ最後に(j+1)段登ってきた時の場合数
    vector<VI> dp(n+4, VI(3, 0));
    dp[1][0] = dp[2][1] = dp[3][2] = 1;
    FOR(i, 1, n){
        dp[i+1][0] = (dp[i][1] + dp[i][2]) % MOD;
        dp[i+2][1] = (dp[i][0] + dp[i][2]) % MOD;
        dp[i+3][2] = (dp[i][0] + dp[i][1]) % MOD;
    }
    cout << ((dp[n][0] + dp[n][1]) % MOD + dp[n][2]) % MOD << "\n";
    return 0;
}