#include <bits/stdc++.h>
using namespace std;
#define int long long
#define ff first
#define ss second
#define sz(a) (int)(a).size()
#define all(a) (a).begin(),(a).end()
#define pb push_back
vector<vector<int>> adj;
vector<int> L, R;
vector<bool> vis;
void dfs(int u) {
R.pb(u);
vis[u] = 1;
for(int v : adj[u]) {
if(!vis[v]) dfs(v);
}
}
bool check(vector<int> &a) {
int cnt = 0;
for(int &u : a) {
cnt += sz(adj[u]);
}
int n = sz(a);
return cnt == (n * (n - 1));
}
signed main() {
ios_base::sync_with_stdio(0);cin.tie(0);
int n, m;
cin >> n >> m;
adj.assign(n, {});
for(int i = 0; i < m; i++) {
int u, v;
cin >> u >> v;
u--;
v--;
adj[u].pb(v);
adj[v].pb(u);
}
vis.assign(n, 0);
int cnt = 0;
for(int i = 0; i < n; i++) {
if(!vis[i]) {
if(cnt == 1) {
L = R;
R.clear();
}
cnt++;
dfs(i);
}
}
if(cnt > 2) {
cout << "NE\n";
return 0;
}
if(cnt == 1) {
cout << (check(R) ? "DA" : "NE");
} else {
cout << (check(R) && check(L) ? "DA" : "NE");
}
return 0;
}
