#include<bits/stdc++.h>
using namespace std;
int h=0,n,d;
vector <int> a[123456];
bool vis[123456]={0};
void dfc(int c,int qd){
	if(c==d+1) return;
	//cout<<a[qd];
	for(int i=0;i<a[qd].size();i++){
		//cout<<a[qd][i]<<" ";
		if(vis[a[qd][i]]==0){
			h++;
			vis[a[qd][i]]=1;
			dfc(c+1,a[qd][i]);
		}
	}
}
int main(){
	cin>>n>>d;
	//cout<<n;
	for(int i=1;i<=n-1;i++){
		//cout<<i;
		int x,y;
		cin>>x>>y;
		//cout<<i;
		a[x].push_back(y);
		//cout<<i;
	}
	dfc(1,1);
	cout<<h;
	return 0;
}