#include<iostream>
#include<cstring>
using namespace std;
int main() {
char s[101], ss[101];
cin.getline(s, 101);
cin.getline(ss, 101);
int k = 0;
char * p = strstr(s, ss);
while (p != NULL) {
k++;
p = strstr(p + 1, ss);
}
if (k == 1)
cout << "Da";
else
cout << "Nu";
return 0;
}