#include<iostream> #include<string> #include<iomanip> #include<cmath> #include<vector> #include<algorithm> using namespace std; #define int long long #define endl "\n" const long long INF = (long long)1e18; const long long MOD = 1'000'000'007; string yn(bool f){return f?"Yes":"No";} string YN(bool f){return f?"YES":"NO";} long long power(long long x, long long n){ long long ans = 1; for(;n;n>>=1,x*=x,ans%=MOD,x%=MOD) if(n&1)ans*=x; return ans%MOD; } template<typename type> vector<vector<type>> product(vector<vector<type>> &a, vector<vector<type>> &b){ vector<vector<type>> res(a.size(),vector<type>(b[0].size(),0)); for(int i = 0; i < a.size(); i++){ for(int j = 0; j < b[0].size(); j++){ for(int k = 0; k < b.size(); k++){ res[i][j] += a[i][k]*b[k][j]; res[i][j] %= MOD; } } } return res; } template<typename type> vector<vector<type>> matrix_power(vector<vector<type>> matrix, long long n){ vector<vector<type>> res(matrix.size(), vector<type>(matrix.size(),0)); for(int i = 0; i < matrix.size(); i++) res[i][i] = 1; for( ; n > 0; n >>= 1){ if(n&1) res = product(res,matrix); matrix = product(matrix,matrix); } return res; } signed main(){ cin.tie(nullptr); ios::sync_with_stdio(false); cout<<fixed<<setprecision(10); int N; int com = 1; cin>>N; com = (N-2) % MOD * ((N-3)%MOD); com %= MOD; com *= power(2, MOD-2); com %= MOD; if((N - 4)%3 == 0){ int x = ((N-4) + 2)/2 - 1; int ans = com; ans = (ans + MOD - x*3%MOD); ans = (MOD - 1 + ans)%MOD; ans *= power(6, MOD-2); ans %= MOD; ans += x; ans++; ans %= MOD; cout<<ans<<endl; } else { int x = ((N-4) + 2)/2; int ans = com; ans = (ans + MOD - x*3%MOD); ans *= power(6, MOD-2); ans %= MOD; ans += x; ans %= MOD; cout<<ans<<endl; } return 0; }