#include //#include using namespace std; #define INF 1.1e9 #define LINF 1.1e18 #define FOR(i,a,b) for (int i=(a);i<(b);++i) #define REP(i,n) FOR(i,0,n) #define ALL(v) (v).begin(),(v).end() #define pb push_back #define pf push_front #define fi first #define se second #define BIT(x,n) bitset(x) #define PI 3.14159265358979323846 typedef long long ll; typedef pair P; typedef pair PP; //----------------------------------------------------------------------------- int n; ll dp[1000010][3]; const int MOD=1e9+7; int main() { cin.tie(0); ios::sync_with_stdio(false); cin>>n; dp[1][0]=dp[2][1]=dp[3][2]=1; FOR(i,1,n+1) { REP(j,3) { REP(k,3) { if(j==k) continue; if(j>=i) continue; dp[i][j]+=dp[i-j-1][k]; dp[i][j]%=MOD; } } } cout<<((dp[n][0]+dp[n][1])%MOD+dp[n][2])%MOD<