//#pragma GCC optimize("Ofast,unroll-loops,O3")
//#pragma GCC optimize("avx,avx2,sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,fma,tune=native")
#include<bits/stdc++.h>
//#include<bits/extc++.h>
//#pragma pack(1)
#define fast ios::sync_with_stdio(0); cin.tie(0);
#define int long long
#define pii pair<int,int>
#define x first
#define y second
#define N 415
using namespace std;
//using namespace __gnu_pbds;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
//typedef tree<int, null_type,less_equal<int>, rb_tree_tag,tree_order_statistics_node_update> order_multiset;
//typedef tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update> order_set;
int n,k,dep[N],dp[(1<<20)+5];
pii cover[N];
vector<int>g[N],use,path;
void dfs(int p,int lp){
dep[p]=dep[lp]+1;
if (dep[p]>k+1)
return;
cover[p].x=use.size();
if (p!=0) path.push_back(p);
for (auto i:g[p]){
if (i!=lp)
dfs(i,p);
}
if (dep[p]==k+1)
use.push_back(p);
cover[p].y=use.size()-1;
}
signed main(){
fast
cin>>n>>k;
for (int i=1;i<n;i++){
int a,b; cin>>a>>b;
a--; b--;
g[a].push_back(b);
g[b].push_back(a);
}
dfs(0,0);
/*
cout<<'\n';
for (int i=0;i<n;i++)
cout<<dep[i]<<" ";
cout<<'\n';
for (auto i:use)
cout<<i<<" ";
cout<<'\n';
for (auto i:path)
cout<<i<<" ";
cout<<'\n';
for (int i=0;i<n;i++)
cout<<cover[i].x<<" "<<cover[i].y<<'\n';
*/
dp[0]=-1;
int ans=0;
for (int i=1;i<(1LL<<k);i++){
dp[i]=-1;
for (auto j:path){
int take=dep[j]-2,last=i-(1LL<<take);
if (i&(1LL<<take)){
if (cover[j].x>cover[j].y) continue;
if (dp[last]==cover[j].x-1){
dp[i]=max(dp[i],cover[j].y);
}
}
}
if (dp[i]==(int)(use.size()-1)) ans=1;
}
if (ans) cout<<"DA\n";
else cout<<"NE\n";
}
