func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int n;     cin >> n;     int p = n + 1;     int cnt = 0;     cout << ((n + 1) * 3) + 1 << endl;     for (int i = 0; i < p; i++) {       cout << i <<     << i << endl;       cout << i + 1 <<     << i << endl;       cout << i <<     << i + 1 << endl;       cnt += 3;     }     cout << p <<     << p << endl;   }   