#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; #define rep(i,a,n) for(int (i)=(a); (i)<(n); (i)++) #define repq(i,a,n) for(int (i)=(a); (i)<=(n); (i)++) #define repr(i,a,n) for(int (i)=(a); (i)>=(n); (i)--) #define all(v) begin(v), end(v) #define pb(a) push_back(a) #define fr first #define sc second #define INF 2000000000 #define int long long int #define X real() #define Y imag() #define EPS (1e-10) #define EQ(a,b) (abs((a) - (b)) < EPS) #define EQV(a,b) ( EQ((a).X, (b).X) && EQ((a).Y, (b).Y) ) #define LE(n, m) ((n) < (m) + EPS) #define LEQ(n, m) ((n) <= (m) + EPS) #define GE(n, m) ((n) + EPS > (m)) #define GEQ(n, m) ((n) + EPS >= (m)) typedef vector VI; typedef vector MAT; typedef pair pii; typedef long long ll; typedef complex P; typedef pair L; typedef pair C; int dx[]={1, -1, 0, 0}; int dy[]={0, 0, 1, -1}; int const MOD = 1000000007; ll mod_pow(ll x, ll n) {return (!n)?1:(mod_pow((x*x)%MOD,n/2)*((n&1)?x:1))%MOD;} int madd(int a, int b) {return (a + b) % MOD;} int msub(int a, int b) {return (a - b + MOD) % MOD;} int mmul(int a, int b) {return (a * b) % MOD;} int minv(int a) {return mod_pow(a, MOD-2);} int mdiv(int a, int b) {return mmul(a, minv(b));} namespace std { bool operator<(const P& a, const P& b) { return a.X != b.X ? a.X < b.X : a.Y < b.Y; } } int dp[1000010][3]; signed main() { int n; cin >> n; int ans = 0; memset(dp, 0, sizeof(dp)); dp[0][0] = 1; rep(i,0,n) rep(j,0,3) { // ken if(j+1 < 3) dp[i+1][j+1] = madd(dp[i+1][j+1], dp[i][j]); // pa if(j != 0) dp[i+1][0] = madd(dp[i+1][0], dp[i][j]); } // repq(i,0,n) rep(j,0,3) printf("dp[%lld][%lld] = %lld\n", i, j, dp[i][j]); rep(i,0,3) ans = madd(ans, dp[n][i]); cout << ans << endl; return 0; }