#include<bits/stdc++.h> 
using namespace std; 
int main() 
{
 int a, b, c; 
 cin >> a >> b >> c; 
 if (a + b > c && b + c > a && a + c > b) 
 { 
 if (a == b && b == c) 
 { 
 cout << "db"; 
 } 
 else if (a == b || b ==c || a == c) 
 { 
 cout << "dy"; 
 } 
 else 
 cout << "yb"; 
 } 
 return 0; 
}