#include<iostream> #include<vector> #include<map> #include<string> #include<cstring> #include<bitset> #include<stack> #include<queue> #include<cmath> #include<algorithm> #include<cstdio> #include<numeric> #include<set> using namespace std; template<class T>inline bool chmin(T& a,T b){ if(a>b){ a=b; return true; } return false; } template<class T>inline bool chmax(T& a,T b){ if(a<b){ a=b; return true; } return false; } const int dx[4]={1,0,-1,0}; const int dy[4]={0,1,0,-1}; #define rep(i,x) for(int i=0;i<x;i++) #define re(i,x,y) for(int i=x;i<y;i++) const long long INF=1e9; const long long mod=1e9+7; #define ll long long int n; ll dp[1000100][3]={0}; int main(){ cin>>n; rep(i,n){ rep(j,3){ dp[i][j]=0; } } dp[1][1]=1; re(i,1,n){ rep(j,3){ if(j==0){ (dp[i+1][1]+=dp[i][0])%=mod; } else if(j==1){ (dp[i+1][0]+=dp[i][1])%=mod; (dp[i+1][2]+=dp[i][1])%=mod; } else if(j==2){ (dp[i+1][0]+=dp[i][2])%=mod; } } } ll ans=0; rep(i,3){ (ans+=dp[n][i])%=mod; } cout<<ans%mod<<endl; return 0; }