#include <iostream>
using namespace std;
int main()
{
     int n, i;
   string x = "Yardi";
   cin >> n;
   string v[n];
   for(i = 0;i < n;i++)
   {
       cin >> v[i];
       if(i == 0)
       {    if(v[i] == x)
            {
                cout << "YES";
            }
            else
            {
                if(v[i]!= x)
                cout << "NO";
            }
       }
   }
   return 0;
}