#include<bits/stdc++.h>
typedef long long ll;
using namespace std;
const int N = 401;
int d[N], g[N];
vector<int> wd[N], G[N];
void dfs1(int s, int p) {
d[s] = d[p] + 1;
wd[d[s]].push_back(s);
for (auto u : G[s]) {
if (u == p) continue;
dfs1(u, s);
}
}
void dfs2(int s, int p, int k) {
if (d[s] == k) g[s] = 1;
else g[s] = 0;
for (auto u : G[s]) {
if (u == p) continue;
dfs2(u, s, k);
g[s] += g[u];
}
}
int main()
{
// ifstream cin("input.txt");
// ofstream cout("output.txt");
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int n, k; cin >> n >> k;
for (int i = 0; i < n - 1; i++) {
int u, v; cin >> u >> v;
u--; v--;
G[u].push_back(v);
G[v].push_back(u);
}
dfs1(0, 0);
dfs2(0, 0, k + 1);
vector<int> cur(1, 0);
for (int i = 0; i < k - 1; i++) {
if (cur.size() == 0) break;
int best_i = cur[0], mx = g[cur[0]];
for (auto u : cur) {
if (g[u] > mx) {
best_i = u;
mx = g[u];
}
}
vector<int> ncur;
for (auto u : cur) {
if (u != best_i) {
for (auto v : G[u]) {
if (d[v] > d[u])ncur.push_back(v);
}
}
}
swap(cur, ncur);
}
int ans = 0;
for (auto u : cur) ans += G[u].size() - 1;
if (ans == 0) {
cout << "DA\n";
} else {
cout << "NE\n";
}
}
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