#include<stdio.h> #include<iostream> #include<algorithm> #include<vector> #include<string> #include<utility> #include<map> #include<set> #include<queue> #include<stack> #include<functional> #include<math.h> #include<random> #include <bitset> #include <cassert> #include <complex> using namespace std; #define N (1000000000+7) //#define N 998244353 #define INF 1e16 typedef long long ll; typedef pair<ll,ll> P; typedef pair<int,P> Q; ll dp[1000010][3]; int main() { int n; cin>>n; dp[0][0]=1; for(int i=0;i<n;i++){ dp[i+1][0] = (dp[i+1][0]+(dp[i][1]+dp[i][2])%N)%N; dp[i+1][1] = (dp[i][0]+dp[i+1][1])%N; dp[i+1][2] = (dp[i+1][2]+dp[i][1])%N; } ll ans = ((dp[n][0]+dp[n][1])%N+dp[n][2])%N; cout<<ans<<endl; }