#include <iostream>
using namespace std;
 
const int MAX_SIZE = 9;
 
int main() {
    int lineSize, colSize;
    cin >> lineSize >> colSize;
    int currentEl, firstEl = 0, areEqual = 1;
    for (int line = 1; line <= colSize; ++line) {
        for (int col = 1; col <= lineSize; ++col) {
            cin >> currentEl;
            if (line == 1 && col == lineSize / 2 + 1) {
                firstEl = currentEl;
            }
            if (((col == lineSize / 2 + 1 && currentEl != 
                firstEl) || (line == colSize / 2 + 1 && 
                currentEl != firstEl)) && areEqual == 1) {
                areEqual = 0;
            }
        }
    }
    if (areEqual == 1) {
        cout << "Da";
    } else {
        cout << "Nu";
    }
    return 0;
}

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NSA1CjEgMiAzIDQgNQoxIDIgMyA0IDUKMyAzIDYgMyAzCjEgMiAzIDQgNSAKMSAyIDMgNCA1

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1 2 3 4 5
1 2 3 4 5
3 3 6 3 3
1 2 3 4 5 
1 2 3 4 5