#include<iostream>
using namespace std;

int main()
{
    long long a1,a2,a3;
    cin>>a1>>a2>>a3;
    if(a1==10&&a2!=10&&a3!=10) cout<<"dung";
    else if(a2==10&&a1!=10&&a3!=10) cout<<"dung";
    else if(a3==10&&a1!=10&&a2!=10) cout<<"dung";
	else cout<<"sai";
	return 0;