#include<bits/stdc++.h>
using namespace std;
#define lalala ios_base::sync_with_stdio(false);cin.tie(NULL);
//#define endl "\n"
#define ll long long
#define pb push_back
#define N 1005
#define f first
#define s second
#define M 17
int dp[N];
int main(){
int n,k;cin>>n>>k;
int ilk[n];
string str;cin>>str;
for(int i=0;i<n;i++){
ilk[i]=(str[i]=='o');
}
int arr[n-1][n];
for(int i=0;i<n-1;i++){
cin>>str;
for(int j=0;j<n;j++){
int a=(str[j]=='o');
arr[i][j]=ilk[j]^a;
}
}
//cout<<ilk[0]<<" "<<ilk[1]<<endl;
//cout<<arr[0][0]<<" "<<arr[0][1]<<endl;
ll int cev=0;
for(int i=0;i<n-1;i++){
for(int j=0;j<n;j++){
dp[i]+=arr[i][j];
}
if(dp[i]<=n-dp[i])cev+=dp[i];
else cev+=(n-dp[i]);
}
if(cev<=k)cout<<"DA"<<endl;
else cout<<"NE"<<endl;
}
