#include <bits/stdc++.h>
using namespace std;
#define bit(i, x) (x >> i & 1)
#define ll long long
#define sz(x) (int)x.size()
const int N = 2e5 + 5;
const int mod = 998244353;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
ll rnd(ll l, ll r) {
return uniform_int_distribution<ll>(l, r)(rng);
}
template<typename T> void minimize(T &x, T y) {
x = min(x, y);
}
int n, k;
vector<vector<int>> G;
vector<int> h;
vector<int> in;
vector<int> parr;
int cnt;
vector<vector<int>> lca;
vector<vector<int>> dp;
void dfs(int u, int par) {
in[u] = ++cnt;
parr[u] = par;
for(int v : G[u]) if(v != par) {
h[v] = h[u] + 1;
dfs(v, u);
}
}
void prepare() {
dfs(1, -1);
auto calc = [&](int x, int y) -> int {
while(x != y) {
if(h[x] < h[y]) swap(x, y);
x = parr[x];
}
return x;
};
for(int i = 1; i <= n; i++) {
for(int j = 1; j <= n; j++) {
lca[i][j] = calc(i, j);
}
}
}
signed main(int argc, char* argv[]) {
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
cin >> n >> k;
G.assign(n + 1, vector<int>(0));
h.assign(n + 1, 0);
in.assign(n + 1, 0);
parr.assign(n + 1, 0);
lca.assign(n + 1, vector<int>(n + 1, 0));
for(int i = 1; i < n; i++) {
int x, y; cin >> x >> y;
G[x].push_back(y);
G[y].push_back(x);
}
prepare();
// for(int i = 1; i <= n; i++) {
// for(int j = 1; j <= n; j++) {
// cout << i << " " << j << " " << lca[i][j] << "\n";
// }
// }
// for(int i = 1; i <= n; i++) {
// cout << in[i] << " ";
// }
vector<int> v;
v.push_back(0);
for(int i = 1; i <= n; i++) {
if(h[i] == k) {
v.push_back(i);
}
}
int m = sz(v) - 1;
dp.assign(m + 1, vector<int>(m + 1, 1e9));
dp[0][0] = 0;
for(int i = 1; i <= m; i++) {
for(int j = 1; j <= i; j++) {
for(int l = 0; l < i; l++) {
int p = lca[v[l + 1]][v[i]];
if(h[p] >= j) {
minimize(dp[i][j], dp[l][j - 1] + 1);
}
}
}
}
int res = 1e9;
for(int i = 1; i <= m; i++) {
minimize(res, dp[m][i]);
}
if(res <= k) cout << "DA";
else cout << "NE";
return 0 ^ 0;
}
