func_code_string: #include <bits/stdc++.h>   using namespace std;   const unsigned long long Mode = 1e9 + 7;   void Modulo(unsigned long long &x) { x = ((x % Mode + Mode) % Mode); }   unsigned long long Pow(unsigned long long x, unsigned long long y) {     unsigned long long res = 1;     for (unsigned long long i = 0; (1ULL << i) <= y; i++, x *= x, Modulo(x))       if (y & (1ULL << i)) res *= x, Modulo(res);     return res;   }   int main() {     unsigned long long n, ans = 1, D = 1;     cin >> n;     D = n;     for (unsigned long long i = 2ULL * n - 1; i > 0; i--) ans *= i, Modulo(ans);     for (unsigned long long i = 1; i <= n - 1; i++) D *= i * i, Modulo(D);     ans *= Pow(D, Mode - 2);     ans *= 2ULL;     Modulo(ans);     ans -= n;     Modulo(ans);     cout << ans << endl;     return 0;   }   