#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#define FAST_IO ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);cerr.tie(0)
#define pb push_back
#define all(x) begin(x), end(x)
#define umap unordered_map
#define space " "
#define TEST_CASES int a; cin >> a; for (int i = 0; i < a; i++) {solve(); cout << endl;}
using namespace std;
using namespace __gnu_pbds;
typedef long long ll;
typedef long double ld;
template<typename T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
mt19937 rng((uint32_t)chrono::steady_clock::now().time_since_epoch().count());
void solve() {
int n, k; cin >> n >> k;
vector<vector<int>> adj(n);
for (int i = 1; i < n; i++) {
int x, y; cin >> x >> y; x--; y--;
adj[x].pb(y);
adj[y].pb(x);
}
vector<int> dp(n, 1);
auto dfs = [&] (auto &&self, int node, int parent) -> void {
vector<int> goes;
for (auto x : adj[node]) {
if (x == parent) {
continue;
}
self(self, x, node);
goes.pb(dp[x]);
}
sort(all(goes));
if (goes.size() >= 2) {
dp[node] = goes[goes.size() - 2] + 1;
}
};
dfs(dfs, 0, -1);
cout << (dp[0] <= k ? "DA" : "NE");
}
int main() {
FAST_IO;
//freopen("guard.in", "r", stdin);
//freopen("guard.out", "w", stdout);
//TEST_CASES;
solve(); cout << endl;
/*int a; cin >> a;
for (int i = 1; i <= a; i++){
cout << "Case #" << i << ": ";
solve();
cout << endl;
}*/
}
