func_code_string: #include <bits/stdc++.h>   struct stack {     char a[1000010];     int top;   } st;   void push(char val) { st.a[st.top++] = val; }   int pop() { return st.a[--st.top]; }   int empty() { return st.top == 0; }   char s[1000010];   int main() {     char t;     int i, cnt = 0;     gets(s);     st.top = 0;     for (i = 0; s[i]; i++) {       if (s[i] ==  [  || s[i] ==  <  || s[i] ==  (  || s[i] ==  { )         push(s[i]);       else {         if (empty()) {           printf( Impossible );           return 0;         }         t = pop();         if (t ==  (  && s[i] !=  )  || t ==  <  && s[i] !=  >  ||             t ==  [  && s[i] !=  ]  || t ==  {  && s[i] !=  } )           cnt++;       }     }     if (!empty()) {       printf( Impossible );       return 0;     }     printf( %d , cnt);     return 0;   }   