func_code_string: #include <bits/stdc++.h>   using namespace std;   const int maxn = 1e3 + 3;   char ch;   bool flag = 0;   void read(int &x) {     for (ch = getchar(); !isdigit(ch) && ((flag |= (ch ==  - )) || 1);          ch = getchar())       ;     for (x = 0; isdigit(ch); x = (x << 1) + (x << 3) + ch - 48, ch = getchar())       ;     x *= 1 - 2 * flag;   }   string ans =   ;   bool h = 0;   string s;   void fu() {     if (cin >> s) {       ans += s;       if (s ==  pair ) {         ans +=  < ;         fu();         ans +=  , ;         fu();         ans +=  > ;       }     } else {       h = 1;     }     if (h) return;   }   int main() {     int n;     read(n);     fu();     if (h || (cin >> s))       cout <<  Error occurred  << endl;     else       cout << ans << endl;     return 0;   }   