func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     string str;     cin >> str;     stack<char> s;     map<char, char> type = {{ ( ,  ) }, { { ,  } }, { < ,  > }, { [ ,  ] }};     int ans = 0;     for (auto it : str) {       if (it ==  {  || it ==  (  || it ==  <  || it ==  [ ) {         s.push(it);       } else {         if (s.empty()) {           cout <<  Impossible n ;           return 0;         } else {           if (type[s.top()] != it) {             ans += 1;           }           s.pop();         }       }     }     if (s.empty()) {       cout << ans <<   n ;       return 0;     }     cout <<  Impossible n ;     return 0;   }   