func_code_string: #include <bits/stdc++.h>   using namespace std;   static const double EPS = 1e-10;   template <typename T, typename S>   vector<T>& operator<<(vector<T>& a, S b) {     a.push_back(b);     return a;   }   template <typename T>   void operator>>(vector<T>& a, int b) {     while (b--)       if (!a.empty()) a.pop_back();   }   bool isprime(int n) {     if (n < 2) return false;     for (int i = 2; i * i <= n; i++)       if (n % i == 0) return false;     return true;   }   long long b_pow(long long x, long long n) {     return n ? b_pow(x * x, n / 2) * (n % 2 ? x : 1) : 1ll;   }   string itos(int n) {     stringstream ss;     ss << n;     return ss.str();   }   string read() {     string s;     char c;     while (cin >> c && c !=  > ) s += c;     if (s.size() == 0) exit(0);     return s.substr(1);   }   int f(string s) { return s[0] ==  / ; }   string get(string s) {     if (s[0] ==  / ) return s.substr(1);     return s;   }   int main() {     ios_base::sync_with_stdio(false);     int n, m, ret = 0;     stack<string> s;     while (1) {       string t = read();       if (t ==   ) return 0;       if (s.size() == 0 || (!f(t) || get(s.top()) != get(t))) {         cout << string(s.size() * 2,    ) <<  <  << t <<  >  << endl;         s.push(t);       } else {         s.pop();         cout << string(s.size() * 2,    ) <<  <  << t <<  >  << endl;       }     }   }   