#include<bits/stdc++.h>
using namespace std;
using ll = long long;
const ll N = 1e3 + 2;
ll a[N][N], c[N];
int main() {
	ll n, m, can, r, x, y, i, j, ans, t;
	cin >> n >> m;
	
	for (i = 1; i <= m; i++) {
		cin >> x >> y;
		a[x][y] = a[y][x] = 1;
	}
	c[1] = 1;
	for (i = 2; i <= n; i++) {
		if ( a[1][i] == 1) {
			c[i] = 0;
		}
		else {
			c[i] = 1;
		}
	}
	can = 1;
	for (i = 1; i <= n; i ++) {
		for (j = i + 1; j <= n; j ++) {
			if ( a[i][j] == 1) {
				if ( c[i] + c[j] != 1) {
					can =0 ;
				}
			}
			else {
				if ( c[i] + c[j] == 1) can = 0;
			}
		}
	}
	if ( can == 1) {
		cout << "DA" << endl;
		return 0;
	}
	for (i = 1; i <= n; i ++) c[i] ^= 1;
	can = 1;
	for (i = 1; i <= n; i ++) {
		for (j = i + 1; j <= n; j ++) {
			if ( a[i][j] == 1) {
				if ( c[i] + c[j] != 1) {
					can =0 ;
				}
			}
			else {
				if ( c[i] + c[j] == 1) can = 0;
			}
		}
	}
	if ( can == 1) {
		cout << "DA" << endl;
		return 0;
	}
	cout <<"NE" << endl;
}
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