#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;
}
