#include "bits/stdc++.h" using namespace std; #define DEBUG(x) cout<<#x<<": "<<x<<endl; #define DEBUG_VEC(v) cout<<#v<<":";for(int i=0;i<v.size();i++) cout<<" "<<v[i]; cout<<endl typedef long long ll; #define vi vector<int> #define vl vector<ll> #define vii vector< vector<int> > #define vll vector< vector<ll> > #define vs vector<string> #define pii pair<int,int> #define pis pair<int,string> #define psi pair<string,int> const int inf = 1000000001; const ll INF = 1e16; #define MOD 1000000007 #define mod 1000000009 #define pi 3.14159265358979323846 #define Sp(p) cout<<setprecision(15)<<fixed<<p<<endl; int dx[4] = { 1,0,-1,0 }, dy[4] = { 0,1,0,-1 }; #define M 1000007 int main() { ll n, i, j; cin >> n; ll n1 = n / 2; ll n2 = n / 2 + 1; ll ans = max((n%M + (n%M)*(n1%M) - (n1%M)*(n1%M)) % M, (n%M + (n%M)*(n2%M) - (n2%M)*(n2%M)) % M); if (ans < 0) { for (i = 0; ans < 0; i++) { ans += M; } } cout << ans << endl; }