#include <bits/stdc++.h>
//#define int long long

using namespace std;
using LL = long long;
using P = pair<int, int>;
using Tapris = tuple<int, int, int>;

#define FOR(i, a, n) for(int i = (int)(a); i < (int)(n); ++i)
#define REP(i, n) FOR(i, 0, n)

#define pb(a) push_back(a)
#define all(x) (x).begin(),(x).end()

const int INF = (int)1e9;
const LL INFL = (LL)1e15;
const int MOD = 1e9 + 7;

int dy[]={0, 0, 1, -1, 0};
int dx[]={1, -1, 0, 0, 0};

/*************** using variables ***************/
int n;
LL dp[1000005][3]; // dp[i][j] := iマス目のときj(0: パ, 1~2: ケンj回目)となる組み合わせの総数
/**********************************************/

signed main(){
    cin.tie(0);
    ios::sync_with_stdio(false);

    cin >> n;
    REP(i, 1000005) REP(j, 3) dp[i][j] = 0;
    dp[1][1] = 1;
    for(int i = 2; i <= n; i++){
        dp[i][0] = (dp[i-1][1] + dp[i-1][2]) % MOD;
        dp[i][1] = dp[i-1][0];
        dp[i][2] = dp[i-1][1];
    }
    cout << (dp[n][0] + dp[n][1] + dp[n][2]) % MOD << endl;
}