Pagini recente » Cod sursa (job #1748584) | Cod sursa (job #1305862) | Cod sursa (job #2219139) | Cod sursa (job #358925) | Cod sursa (job #1680047)
#include <fstream>
using namespace std;
ifstream in("dirichlet.in");
ofstream out("dirichlet.out");
const int MOD = 9999991;
int fastExp(int base, int exp) {
if(exp == 0) return 1;
int halfPower = fastExp(base, exp >> 1);
if(exp & 1) return 1LL * halfPower * halfPower % MOD * base % MOD;
return 1LL * halfPower * halfPower % MOD;
}
int getComb(int n, int k) {
int ans = 1;
for(int i = 1; i <= k; i++) {
ans = 1LL * ans * (n - i + 1) * fastExp(i, MOD - 2) % MOD;
}
return ans;
}
int main() {
int n;
in >> n;
out << 1LL * getComb(2*n, n) * fastExp(n + 1, MOD - 2) % MOD << '\n';
return 0;
}