#include using namespace std; #define int long long constexpr int inf = 1e18; constexpr int maxn = 2e5 + 5; constexpr int mod = 998244353; constexpr int P = 1000000007; // assume -P <= x < 2P int norm(int x) { if (x < 0) x += P; if (x >= P) x -= P; return x; } template T qpow(T a, int b) { T res = 1; for (; b; b /= 2, a *= a) { if (b % 2) res *= a; } return res; } struct Z { int x; Z(int x = 0) : x(norm(x)){} int val()const{return x;} Z operator - ()const{return Z(norm(P - x));} Z inv()const {assert(x != 0); return qpow(*this, P - 2);} Z &operator *= (const Z &rhs){x = x * rhs.x % P; return *this;} Z &operator += (const Z &rhs){x = norm(x + rhs.x); return *this;} Z &operator -= (const Z &rhs){x = norm(x - rhs.x); return *this;} Z &operator /= (const Z &rhs){return *this *= rhs.inv();} friend Z operator * (const Z &lhs, const Z &rhs){Z ret = lhs; ret *= rhs; return ret;} friend Z operator + (const Z &lhs, const Z &rhs){Z ret = lhs; ret += rhs; return ret;} friend Z operator - (const Z &lhs, const Z &rhs){Z ret = lhs; ret -= rhs; return ret;} friend Z operator / (const Z &lhs, const Z &rhs){Z ret = lhs; ret /= rhs; return ret;} }; inline void solve() { int n; cin >> n; vector f(n + 1, vector(n + 1)); f[0][0] = 1; for(int i = 1; i <= n; i ++) { for (int j = 0; j <= n; j ++) { f[i][j] = f[i - 1][j]; if (j >= i && i >= 3) { f[i][j] += f[i][j - i]; } } } cout << f[n][n].val() << "\n"; } signed main() { ios::sync_with_stdio(false); cin.tie(nullptr); solve(); return 0; } /* The details you should care: */