#include <iostream>

using namespace std;

int main()
{
    int n1, n2, i=0;
    cin>>n1>>n2;
    while((n1!=0) && (n2!=0))
    {
        if(n1%10==n2%10) i++;
        n1=n1/10;
        n2=n2/10;
    }
    if((n1==0) && (n2==0))
    {
        cout<<"DA"<<endl;
        cout<<i;
    }
    else cout<<"NU";
    return 0;
}