#include <bits/stdc++.h>
#define fi first
#define se second
#define mp make_pair
using namespace std;
const int N = 405;
vector <int> tmpadj[N];
vector <int> adj[N];
int par[N][N];
int dp[1 << 20];
int tin[N];
int tout[N];
int id[N];
int h[N];
int n,k,timer;
int getbit(int mask, int i) {
return (mask >> i) & 1;
}
void maxi(int &a, int b) {
if (a < b)
a = b;
}
bool dfs1(int u, int p) {
if (h[u] == k)
return true;
bool res = false;
for (int v : tmpadj[u]) if (v != p) {
h[v] = h[u] + 1;
int nxt = dfs1(v, u);
res |= nxt;
if (nxt)
adj[u].push_back(v);
}
return res;
}
void dfs2(int u, int p) {
par[u][0] = u;
par[u][1] = p;
for (int i = 2; i <= h[u] + 1; i++)
par[u][i] = par[par[u][i - 1]][1];
timer++;
tin[u] = tout[u] = timer;
id[timer] = u;
for (int v : adj[u])
if (v != p)
dfs2(v, u);
tout[u] = timer;
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cin >> n >> k;
if (k > 20)
return cout << "DA\n", 0;
for (int i = 1; i < n; i++) {
int u,v; cin >> u >> v;
tmpadj[u].push_back(v);
tmpadj[v].push_back(u);
}
if (!dfs1(1, -1))
return cout << "DA\n", 0;
dfs2(1, -1);
// for (int i = 1; i <= n; i++)
// cerr << h[i] << " ";
// cerr << timer << "\n";
// for (int i = 1; i <= n; i++)
// cerr << tin[i] << " " << tout[i] << "\n";
for (int mask = 0; mask < (1 << k); mask++) {
int &res = dp[mask];
while (res <= timer && h[id[res]] < k)
res++;
if (res > timer)
return cout << "DA\n", 0;
int u = id[res];
for (int i = 0; i < k; i++) if (!getbit(mask, i)) {
int p = par[u][k - (i + 1)];
maxi(dp[mask | (1 << i)], tout[p] + 1);
}
}
cout << "NE\n";
return 0;
}
