func_code_string: #include <bits/stdc++.h>   using namespace std;   char a[1000011];   int main() {     while (~scanf( %s , a)) {       int t = strlen(a);       if (t % 2 != 0)         printf( Impossible n );       else {         stack<char> sta;         int ans = 0, p = 0;         for (int i = 0; i < t; i++) {           if (a[i] ==  {  || a[i] ==  [  || a[i] ==  (  || a[i] ==  < ) {             sta.push(a[i]);             ans++;           } else {             if (sta.empty()) {               p++;               printf( Impossible n );               break;             } else {               char s = sta.top();               if ((s ==  {  && a[i] ==  } ) || (s ==  (  && a[i] ==  ) ) ||                   (s ==  [  && a[i] ==  ] ) || (s ==  <  && a[i] ==  > )) {                 ans--;               }               sta.pop();             }           }         }         if (p == 0) {           if (sta.empty()) {             if (ans < 0)               printf( Impossible n );             else               printf( %d n , ans);           } else             printf( Impossible n );         }       }       memset(a, 0, sizeof(a));     }     return 0;   }   