20pts求调

#include<bits/stdc++.h>
using namespace std;
#define int long long
#define FIO ios::sync_with_stdio(0),cin.tie(0),cout.tie(0);
const int N = 1e6 + 10;
vector<int> G[N];
int ans, vis[N], n, k;
void dfs(int x, int d){
	if(d <= k) ans++;
	if(d > k) return;
	for(auto to : G[x])
		if(!vis[to]) dfs(to, d + 1);
}
signed main(){
	FIO
	cin >> n >> k;
	for(int i = 1; i < n; i++){
		int u, v;
		cin >> u >> v;
		G[u].push_back(v);
	}
	dfs(1, 0);
	cout << ans - 1;
    return 0;
}