This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#pragma GCC optimize ("O3")
#pragma GCC target ("sse4")
#include<bits/stdc++.h>
using namespace std;
const int maxn=405,sq=20;
int n,k;
vector<int>adj[maxn],dp[maxn];
int cnt[(1<<sq)],nag[maxn],high[maxn],sz,par[maxn];
vector<pair<int,int>>updy[maxn],unnow;
pair<int,int>stf[maxn];
set<pair<int,int>>st;
void vorod(){
cin>>n>>k;
for(int i=0;i<n-1;i++){
int u,v;
cin>>u>>v;
adj[u].push_back(v);
adj[v].push_back(u);
}
if(k>=20){
cout<<"DA\n";
exit(0);
}
}
void del(int u,int x,int len){
if(u==0||x==0){
return ;
}
sort(adj[u].begin(),adj[u].end());
adj[u].erase(lower_bound(adj[u].begin(),adj[u].end(),x));
if((int)adj[u].size()==0){
st.insert(make_pair(len,u));
}
}
void dfs(int u,int len=0,int para=0){
del(u,para,len);
if(len==k){
adj[u].clear();
}
for(auto x:adj[u]){
par[x]=u;
dfs(x,len+1,u);
}
if((int)adj[u].size()==0){
st.insert(make_pair(len,u));
}
}
void dfs2(int u=1,int len=0){
if(adj[u].size()==0){
sz++;
nag[sz]=u;
stf[u].first=stf[u].second=sz;
return ;
}
stf[u].first=sz+1;
for(auto x:adj[u]){
dfs2(x,len+1);
}
stf[u].second=sz;
}
void pre(){
dfs(1);
//cout<<"wtf"<<endl;
while((int)st.size()>0&&((*st.begin()).first<k)){
int u=(*st.begin()).second,v=(*st.begin()).first;
st.erase(*st.begin());
del(par[u],u,v-1);
}
//cout<<"salam"<<endl;
if((int)st.size()==0){
cout<<"DA\n";
exit(0);
}
dfs2();
}
void add(int i,int val){
if(val>=(1<<sq)){
exit(0);
}
//cout<<i<<" "<<val<<" "<<sz<<endl;
if(cnt[val]==0){
cnt[val]++;
dp[i].push_back(val);
}
}
void cl(int i){
for(auto x:dp[i]){
cnt[x]=0;
}
}
void solve(){
for(int i=1;i<=sz;i++){
int u=nag[i];
for(int j=k;j>=1;j--){
//cout<<i<<" "<<u<<" "<<stf[u].first<<" "<<stf[u].second<<endl;
if(stf[u].second==i){
// cout<<"salam: "<<i<<" "<<j<<endl;
updy[i].push_back(make_pair(stf[u].first-1,j));
}
u=par[u];
}
for(auto x:updy[i]){
// cout<<"chy: "<<i<<" "<<x.first<<" "<<x.second<<endl;
if(x.first==0){
add(i,(1<<x.second));
continue;
}
int ind=x.first,z=x.second;
for(auto y:dp[ind]){
if(((y>>z)&1)==0){
add(i,(1<<z)^y);
}
}
}
cl(i);
}
}
void khor(){
if((int)dp[sz].size()==0){
cout<<"NE\n";
}else{
cout<<"DA\n";
}
}
int main(){
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
// freopen("inp.txt","r",stdin);
vorod();
pre();
//cout<<"salam"<<endl;
solve();
khor();
}
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