#include <iostream>
using namespace std;int n,v[100],i=1,x,ok=0;void cit(int &n){ cout<<"n="; cin>>n; if(n>=2&&n<=10) {} else cit(n);}void mem(int n,int v[],int i){
if(i<=n) { cin>>v[i]; if(v[i]>=0&&v[i]<=1000) mem(n,v,i+1); else mem(n,v,i); }}int pozimp(int n,int v[],int x,int i){ if(i<=n) if(v[i]==x&&!(i%2)) ok=1; else pozimp(n,v,x,i+1); return ok;}int main(){ cit(n); mem(n,v,i); cin>>x; if(pozimp(n,v,x,i)) cout<<"Da"; else cout<<"Nu";}