#include <bits/stdc++.h>
using namespace std;
#define sp " "
#define endl "\n"
#define fileio() freopen("input.txt", "r", stdin), freopen("output.txt", "w", stdout)
#define fastio() cin.tie(0), ios_base::sync_with_stdio(0)
#define pb push_back
#define pii pair<int, int>
#define st first
#define nd second
#define N 1005
bitset<N> arr[N];
int dist[N][N];
const int INF = 2e9 + 7;
int32_t main(){
#ifndef ONLINE_JUDGE
//fileio();
#endif
fastio();
int n, k;
cin>>n>>k;
for (int i = 1; i <= n; i++){
for (int j = 1; j <= n; j++){
char c;
cin>>c;
arr[i][j] = c == 'x';
}
}
for (int i = 1; i <= n; i++){
for (int j = i + 1; j <= n; j++){
bitset<N> tmp = arr[i] ^ arr[j];
dist[i][j] = dist[j][i] = tmp.count();
}
}
int ans = INF;
for (int i = 1; i <= n; i++){
int curr = 0;
for (int j = 1; j <= n; j++){
curr += min(dist[i][j], n - dist[i][j]);
}
ans = min(ans, curr);
}
for (int i = 1; i <= n; i++){
int curr = 1;
for (int j = 2; j <= n; j++){
if (arr[j][i] == arr[1][i]) dist[1][j]++;
else dist[1][j]--;
curr += min(dist[1][j], n - dist[1][j]);
if (arr[j][i] == arr[1][i]) dist[1][j]--;
else dist[1][j]++;
}
ans = min(ans, curr);
}
if (ans <= k) cout<<"DA\n";
else cout<<"NE\n";
cerr<<"time taken : "<<(float)clock() / CLOCKS_PER_SEC<<" seconds\n";
}
