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

int prim(int n)
{
    for (int i=2;i<=(n/2)+1;i++)
        if (n%i == 0)
            return 0;
    return 1;
}

int numar(int x, int nrp, int y)
{
    for (int i=y;i<=x;i++)
        if (prim(i))
            nrp++;
    return nrp;
}

int main()
{
    int a,b;
    cin>>a>>b;
    if (numar(b,0,a) > 1)
        cout<<"DA";
    else
        cout<<"NU";
    return 0;
}