func_code_string: #include <bits/stdc++.h>   using namespace std;   const long long N = 1e6 + 5;   long long n;   long long a[N];   int32_t main() {     ios::sync_with_stdio(0);     cin.tie(0);     cout.tie(0);     ;     cin >> n;     if (n == 0) {       cout <<  1 1 ;       return 0;     }     long long l = 1, r = n;     for (long long cur = 1; cur <= n; cur += 2) {       a[l++] = cur;       a[r--] = cur;     }     l = n + 1;     r = 2 * n - 1;     for (long long cur = 2; cur <= n; cur += 2) {       a[l++] = cur;       a[r--] = cur;     }     for (long long i = 1; i <= 2 * n; i++) {       if (a[i] == 0) a[i] = n;       cout << a[i] <<    ;     }     return 0;   }   