#include <bits/stdc++.h> using namespace std; int v[505], n, i, ct; bool ok = true; int main() { cin >> n; cin >> v[1]; for (i = 2; i <= n; i++) { cin >> v[i]; if (v[i] != v[1]) { ok = false; break; } } if (ok) cout << "DA"; else cout << "NU"; return 0; }