func_code_string: #include <bits/stdc++.h>   using namespace std;   long long n;   long long ans[100100 << 1];   long long ksm(long long p, long long q) {     long long res = 1;     while (q) {       if (q & 1) res = res * p % 1000000007;       p = p * p % 1000000007;       q >>= 1;     }     return res;   }   signed main() {     cin >> n;     ans[0] = 1;     for (long long i = 1; i <= (n << 1); i++) {       ans[i] = ans[i - 1] * i % 1000000007;     }     cout << (ans[n << 1] * ksm(ans[n] * ans[n] % 1000000007, 1000000007 - 2)) %                     1000000007 -                 n;     return 0;   }   