func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     ios_base::sync_with_stdio(0);     int n;     while (cin >> n) {       string s;       getline(cin, s);       getline(cin, s);       stringstream ss(s);       string token;       string res =   ;       vector<int> numelements;       bool error = 0;       if (s ==  int ) {         cout <<  int  << endl;         continue;       }       while (ss >> token) {         int cur = numelements.size() - 1;         if (cur >= 0 && numelements[cur] == 1) res +=  , ;         if (token ==  pair ) {           if (cur >= 0) {             numelements[cur]++;             if (numelements[cur] >= 3) {               error = 1;               break;             }           }           res +=  pair< ;           numelements.push_back(0);         } else if (token ==  int ) {           if (cur < 0) {             error = 1;             break;           }           numelements[cur]++;           res +=  int ;           if (numelements[cur] >= 3) {             error = 1;             break;           }           while (numelements.size() > 0 &&                  numelements[numelements.size() - 1] == 2) {             numelements.erase(numelements.end() - 1);             res +=  > ;           }         }       }       if (numelements.size() > 0) error = 1;       if (error)         cout <<  Error occurred  << endl;       else         cout << res << endl;     }   }   