#include <iostream>
#include <bitset>
#include <algorithm>
using namespace std;
int n, k;
bitset <1005> a[1005], b[1005];
int main(){
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
cin >> n >> k;
for(int i = 0 ; i < n ; ++i){
string s;
cin >> s;
for(int j = 0 ; j < n ; ++j){
a[i][j] = (s[j] == 'o');
b[i][j] = a[i][j] ^ 1;
}
}
for(int i = 0 ; i < n ; ++i){
int br = 0;
for(int j = 0 ; j < n ; ++j){
if(i == j)
continue;
int t1 = (a[i] ^ a[j]).count();
int t2 = (a[i] ^ b[j]).count();
int t3 = (b[i] ^ a[j]).count();
int t4 = (b[i] ^ b[j]).count();
br += min(t1, min(t2, min(t3, t4)));
}
if(br <= k){
cout << "DA" << endl;
return 0;
}
}
if(k < n){
cout << "NE" << endl;
return 0;
}
for(int i = 0 ; i < n ; ++i){
a[0][i] = a[0][i] ^ 1;
b[0][i] = b[0][i] ^ 1;
int br = 1;
for(int j = 0 ; j < n ; ++j){
if(i == j)
continue;
int t1 = (a[0] ^ a[j]).count();
int t2 = (a[0] ^ b[j]).count();
int t3 = (b[0] ^ a[j]).count();
int t4 = (b[0] ^ b[j]).count();
br += min(t1, min(t2, min(t3, t4)));
}
if(br <= k){
cout << "DA" << endl;
return 0;
}
a[0][i] = a[0][i] ^ 1;
b[0][i] = b[0][i] ^ 1;
}
cout << "NE" << endl;
return 0;
}
