#include <bits/stdc++.h>
using namespace std;
const int MOD = 1000000007;
int dp[2][3];

int main(){
    int N; cin >> N;
    int now = 0, pre = 1;
    dp[now][1] = 1;
    for(int i = 1; i < N; i++){
        swap(now,pre);
        dp[now][0] = (dp[pre][1] + dp[pre][2]) % MOD;
        dp[now][1] = dp[pre][0];
        dp[now][2] = dp[pre][1];
    }

    int total = 0;
    for(int i = 0; i < 3; i++){
        (total += dp[now][i]) %= MOD;
    }
    cout << total << endl;
}