#include <iostream>
#include <fstream>
using namespace std;

ifstream f("bac.in");
int main() {

	int a,frecv[1001],i;
	for (i = 0; i <= 1000; i++)
		frecv[i] = 0;
	
    	while (f >> a) {
        	frecv[a] = 1;
	}
	
	int ultim = -1, ok = 0;
	for (i = 0; i <= 1000 && ok == 0; i++) {

		if (frecv[i] != 0) {

			if (ultim != -1) {
				if (i - ultim != 2)
					ok = 1;
			}
			ultim = i;
		}
	}

	if (ok == 0)
		cout<<"DA";
	else
		cout<<"NU";
	return 0;

}