#include <bits/stdc++.h>   using namespace std;   int pos = -1;   void Go(vector<string> &t) {     if (t[++pos] ==  int ) {       cout <<  int ;     } else {       cout <<  pair< ;       Go(t);       cout <<  , ;       Go(t);       cout <<  > ;     }   }   int main() {     int n, i = 0;     bool check = true;     cin >> n;     string t, t1 =   ;     int bal = 0;     int k = 0;     std::vector<std::string> s;     char c;     std::getline(std::cin, t);     std::getline(std::cin, t);     for (int j = 0; j < t.length(); j++) {       if (t[j] !=    ) {         t1 += t[j];       } else {         s.push_back(t1);         t1 =   ;       }     }     s.push_back(t1);     k = s.size();     {       for (int i = 0; i < k - 1; i++) {         if (s[i] ==  pair )           bal++;         else {           bal--;         }         if (bal < 0) {           check = false;         }       }       if (s[k - 1] ==  pair )         bal++;       else {         bal--;       }       if (bal != -1) {         check = false;       }       if (!check) {         cout <<  Error occurred ;         return 0;       }     }     Go(s);   }   