#include using namespace std; #define rep(i,a,b) for(int i=a;i= mod ? x - mod : x; } template int add(int x, T... y) { return add(x, add(y...)); } int mul(int x, int y) { return 1LL * x * y % mod; } template int mul(int x, T... y) { return mul(x, mul(y...)); } int sub(int x, int y) { return add(x, mod - y); } int modpow(int a, long long b) { int ret = 1; while (b > 0) { if (b & 1) ret = 1LL * ret * a % mod; a = 1LL * a * a % mod; b >>= 1; } return ret; } int modinv(int a) { return modpow(a, mod - 2); } int fac[201010], ifac[201010]; void initfac() { fac[0] = ifac[0] = 1; rep(i, 1, 201010) fac[i] = 1LL * i * fac[i - 1] % mod; rep(i, 1, 201010) ifac[i] = modinv(fac[i]); } int aCb(int a, int b) { if (b < 0 || a < b) return 0; return (1LL * fac[a] * ifac[a - b] % mod) * ifac[b] % mod; } //----------------------------------------------------------------------------------- int N; int dp[2020]; //----------------------------------------------------------------------------------- int main() { initfac(); cin >> N; if (N <= 2) { printf("0\n"); return 0; } dp[0] = dp[1] = dp[2] = 1; dp[3] = 2; rep(i, 3, N) for (int j = 0; j <= i;j+=2) { dp[i + 1] = add(dp[i + 1], mul(aCb(i, j), dp[j], dp[i - j])); } cout << mul(dp[N],2) << endl; }