#include <algorithm>
#include <cstdio>
#include <iostream>
#include <map>
#include <cmath>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <vector>
#include <stdlib.h>
#include <stdio.h>
#include <bitset>
using namespace std;

#define ll         long long
#define PI         acos(-1.0)
#define FOR(I,A,B) for(int I = (A); I < (B); ++I)

//方針
//動的計画法dp[連続したケンの数][最後がパかどうか]
//最後がパになる = けんぱorけんけんぱ
//けんがi回続く = ぱ->けんorけん->けん
//dp[i][0] = d[0][1] + dp[i-1][0]
//初期はdp[1][0] = 1

int main(){
    ll MOD = pow(10, 9) + 7;
    int N;
    cin >> N;
    ll dp[3][2];
    FOR(i, 0, 3) FOR(j, 0, 2) dp[i][j] = 0;
    dp[1][0] = 1;
    ll a, b, c;
    FOR(i, 1, N){
        a = (dp[1][0] + dp[2][0]) % MOD;
        b = dp[0][1] % MOD;
        c = dp[1][0] % MOD;
        dp[0][1] = a;
        dp[1][0] = b;
        dp[2][0] = c;
    }
    ll ans = 0;
    ans += (dp[0][1] + dp[1][0] + dp[2][0]) % MOD;
    cout << ans << endl;
}