#include <bits/stdc++.h>
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
template <class T> using ind_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#define sz(x) (int)(x).size()
#define sq(x) (x) * (x)
#define all(x) x.begin(), x.end()
#define chmax(x, y) x = max(x, y)
#define chmin(x, y) x = min(x, y)
#define minc(x, y) x = (x + y) % MOD
#define mdec(x, y) x = ((x - y) % MOD + MOD) % MOD
#define ll long long
#define lll __int128_t
#define ld long double
#define pii pair<int,int>
#define vpii vector<pii>
#define pll pair<ll,ll>
#define vpll vector<pll>
#define vi vector<int>
#define vll vector<ll>
#define vb vector<bool>
#define vvi vector<vector<int>>
#define vvll vector<vector<ll>>
#define f first
#define s second
#define pb push_back
#define popb pop_back
#define bk back
#define popcnt __builtin_popcount
#define FOR(i, a, b) for (int i = (a); i < (b); ++i)
#define F0R(i, a) for (int i = 0; i < (a); ++i)
#define ROF(i, a, b) for (int i = (a)-1; i >= (b); --i)
#define R0F(i, a) for (int i = (a)-1; i >= 0; --i)
string to_string(string s) {
return '"' + s + '"';
}
string to_string(char c) {
return '\'' + string(1,c) + '\'';
}
string to_string(const char* s) {
return to_string((string)s);
}
string to_string(bool b) {
return (b ? "true" : "false");
}
template <typename T1, typename T2>
string to_string(pair<T1, T2> &p) {
return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}
template <typename T>
string to_string(T v) {
int c = 0;
string res = "{";
for (const auto &x : v) {
if (c) res += ", ";
c = 1;
res += to_string(x);
}
res += "}";
return res;
}
void __print(bool b) { cerr << "]" << endl; }
template <typename First, typename... Rest>
void __print(bool b, First F, Rest... R) {
if (b) cerr << ", ";
cerr << to_string(F);
__print(true, R...);
}
#ifdef LOCAL
#define print(...) cerr << "[" << #__VA_ARGS__ << "] : [", __print(false, __VA_ARGS__)
#else
#define print(...) 42
#endif
mt19937_64 rv(chrono::steady_clock::now().time_since_epoch().count());
ll rng(ll l, ll r) { return (ll)uniform_int_distribution<ll>(l, r)(rv); }
struct custom_hash {
static uint64_t splitmix64(uint64_t x) {
x += 0x9e3779b97f4a7c15;
x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
return x ^ (x >> 31);
}
size_t operator()(uint64_t x) const {
static const uint64_t r = chrono::steady_clock::now().time_since_epoch().count();
return splitmix64(x + r);
}
};
ll MOD = 1e9+7;
int M998 = 998244353;
const ll INF = 3e18;
const double PI = 4 * atan(1);
ll p2(int b) { return (1ll << b); }
int l2(int x) { return 31 - __builtin_clz(x); }
int l2(ll x) { return 63 - __builtin_clzll(x); }
ll msum(ll a, ll b, ll m = MOD) { return ((a + b) % m + m) % m; }
ll mdif(ll a, ll b, ll m = MOD) { return ((a - b) % m + m) % m; }
ll mmul(ll a, ll b, ll m = MOD) { return (__int128)a * b % m; }
ll mexp(ll b, ll e, ll m = MOD) {
ll res = 1;
while (e) {
if (e % 2) res = mmul(res, b, m);
b = mmul(b, b, m);
e /= 2;
} return res;
}
ll exp(ll b, ll e) { return mexp(b, e, INF); }
ll minv(ll b, ll m = MOD) { return mexp(b, m-2, m); }
ll mdiv(ll a, ll b, ll m = MOD) { return mmul(a, minv(b), m); }
vll fm = {1}, fmi = {1};
ll fac(int n) {
while (sz(fm) <= n) {
fm.push_back(fm.back() * sz(fm) % MOD);
fmi.push_back(minv(fm.back()));
}
return fm[n];
}
ll ncr(int n, int r) {
return fac(n) * fmi[r] % MOD * fmi[n-r] % MOD;
}
struct DSU {
vector<int> p, c;
DSU(int n) : c(n, 1), p(n) {
for (int i = 0; i < n; ++i) {
p[i] = i;
}
}
int get(int v) {
if (p[v] == v) return v;
return p[v] = get(p[v]);
}
int size(int v) { return c[get(v)]; }
bool same(int x, int y) { return get(x) == get(y); }
bool unite(int x, int y) {
x = get(x); y = get(y);
if (x == y) return 0;
if (c[x] > c[y]) swap(x, y);
p[x] = y;
c[y] += c[x];
return 1;
}
};
template <class T> struct BIT {
int len;
vector<T> bit, v;
BIT(int n) : len(n), bit(n + 1), v(n) {}
void edit(int ind, T val) { add(ind, val - v[ind]); }
void add(int ind, T val) {
v[ind] += val;
ind++;
for (; ind <= len; ind += ind & -ind) { bit[ind] += val; }
}
T sum(int ind) { // [0, ind]
ind++;
T total = 0;
for (; ind > 0; ind -= ind & -ind) { total += bit[ind]; }
return total;
}
T sum(int l, int r) { // [l, r)
return sum(r - 1) - sum(l - 1);
}
};
template<typename T> struct SegTree {
vector<T> v; int len;
T id = 0;
T oper(T a, T b) { // associative operation
return a + b;
}
SegTree(int n) : len(n), v(n*2) { for (int i = 0; i < n*2; ++i) v[i] = id; }
SegTree(vector<T> v_) : len(sz(v_)), v(v_) {}
void edit(int ind, const T &val) {
ind += len; v[ind] = val;
while (ind > 1) {
ind /= 2;
v[ind] = oper(v[ind<<1], v[ind<<1|1]);
}
}
T query(int l, int r) { // [l,r)
T resl = id, resr = id; l += len; r += len;
while (l < r) {
if (l%2) resl = oper(resl, v[l++]);
if (r%2) resr = oper(v[--r], resr);
l /= 2; r /= 2;
}
return oper(resl, resr);
}
T get(int ind) { return v[ind + len]; }
void inc(int ind, T val) { edit(ind, get(ind) + val); }
};
/* CODE BEGINS HERE */
const int N = 2e5 + 5;
vi adj[N];
int dp[N];
void dfs(int v, int p) {
vi ch;
for (auto u : adj[v]) {
if (u == p) return;
dfs(u, v);
ch.pb(dp[u]);
}
sort(all(ch));
if (sz(ch) <= 1) dp[v] = 0;
else dp[v] = ch[sz(ch) - 2] + 1;
}
void solve(int tc_ = 0) {
int n, k; cin >> n >> k;
F0R(i, n - 1) {
int a, b; cin >> a >> b; a--; b--;
adj[a].pb(b);
adj[b].pb(a);
}
dfs(0, -1);
cout << (dp[0] < k ? "DA" : "NE") << '\n';
}
void init() {
//
}
void setio(string s = "") {
ios::sync_with_stdio(false);
cin.tie(nullptr);
// return; // for interactive problems
#ifdef LOCAL
freopen("in.txt", "r", stdin);
freopen("err.txt", "w", stderr);
freopen("out.txt", "w", stdout);
#else
if (sz(s)) {
freopen((s+".in").c_str(), "r", stdin);
freopen((s+".out").c_str(), "w", stdout);
}
#endif
}
int32_t main() {
setio();
init();
int t = 1;
// cin >> t;
for (int i = 0; i < t; ++i) solve(i);
cerr << "Time : " << (double) clock() / CLOCKS_PER_SEC << "s" << endl;
return 0;
}
