#include <bits/stdc++.h>
using namespace std;
const int N = 210000;
const int M = 100001;
const int inf = 1e9;
const long long mod = 1e9 + 7;
int n, k;
vector<int> g[405];
int h[405], deepest[405], node[405], bef[405];
bool dp[405][1 << 21];
void pre_dfs(int u, int p, int cur_h) {
h[u] = deepest[u] = cur_h;
for (int v : g[u]) if (v != p) {
pre_dfs(v, u, cur_h + 1);
deepest[u] = max(deepest[u], deepest[v]);
}
}
int id;
void dfs(int u, int p) {
if (deepest[u] < k || h[u] > k) return;
bef[u] = id;
for (int v : g[u]) if (v != p) {
dfs(v, u);
}
id ++;
node[id] = u;
//cout << id << " : " << u << "\n";
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cin >> n >> k;
int a, b;
for (int i = 1; i < n; i ++) {
cin >> a >> b;
g[a].push_back(b);
g[b].push_back(a);
}
pre_dfs(1, 0, 0);
dfs(1, 0);
int c = (1 << 21);
for (int i = 0; i < c; i ++) {
dp[0][i] = true;
}
for (int i = 1; i < id; i ++) {
int p = h[node[i]] - 1;
int b = bef[node[i]];
if (b == i - 1) {
for (int t = 0; t < c; t ++) {
if ((t >> p) & 1) {
dp[i][t] = dp[i - 1][t - (1 << p)];
}
}
} else {
for (int t = 0; t < c; t ++) {
dp[i][t] = dp[i - 1][t];
if ((t >> p) & 1) {
dp[i][t] |= dp[b][t - (1 << p)];
}
}
}
}
if (dp[id - 1][c - 1]) cout << "DA";
else cout << "NE";
return 0;
}
