#include <bits/stdc++.h>
#define ll long long
#define INF 1000000005
#define MOD 1000000007
#define EPS 1e-10
#define rep(i,n) for(int i=0;i<(int)n;++i)
#define each(a, b) for(auto (a): (b))
#define all(v) (v).begin(),(v).end()
#define fi first
#define se second
#define pb push_back
#define show(x) cout <<#x<<" = "<<(x)<<endl
#define spair(p) cout <<#p<<": "<<p.fi<<" "<<p.se<<endl
#define svec(v) cout<<#v<<":";rep(kbrni,v.size())cout<<" "<<v[kbrni];cout<<endl
#define sset(s) cout<<#s<<":";each(kbrni,s)cout <<" "<<kbrni;cout<<endl

using namespace std;

typedef pair<int,int>P;

const int MAX_N = 1000005;

ll dp[MAX_N][3];

int main()
{
    int n;
    cin >> n;
    dp[1][0] = 1,dp[2][1] = 1,dp[3][0] = 1,dp[3][1] = 1,dp[3][2] = 1;
    for(int i=4;i<=n;i++){
        dp[i][0] = (dp[i-1][1] + dp[i-1][2]) % MOD;
        dp[i][1] = (dp[i-2][0] + dp[i-2][2]) % MOD;
        dp[i][2] = (dp[i-3][0] + dp[i-3][1]) % MOD;
    }
    cout << (dp[n][0] + dp[n][1] + dp[n][2]) % MOD << endl;
    return 0;
}