#include <iostream>
#include <string>
#include <stack>
using namespace std;
int main()
{
  string s;
  cin >> s;
  string otkr = "([{<";
  string zakr = ")]}>";
  int n = s.length();
  stack <char> st;
  bool f = true;
  for (int i = 0; i < n; i++){
    if (otkr.find(s[i]) != -1)
      st.push(s[i]);
    if (zakr.find(s[i]) != -1){
      if (st.empty()){
        f = false;
        break;
      }
      if (zakr.find(s[i]) == otkr.find(st.top()))
        st.pop();
      else{
        f = false;
        break;
      }
    }
  }
  if (st.empty() && f)
    cout << "da";
  else
    cout << "net";
  return 0;
}