#include <bits/stdc++.h>
#define ll long long
#define P 998244353
using namespace std;
const int N=155;
int n,m,k,s,t,ans,p,sz[N],f[N][N],g[N];
vector<int> e[N];
void dfs(int u){
	f[u][1]=0;sz[u]=1;
	for (int &v:e[u]){
		dfs(v);
		memset(g,0x3f,sizeof(g));
		for (int i=1;i<=sz[u];++i){
			g[i]=min(g[i],f[u][i]+1);
			for (int j=1;j<=sz[v];++j)
				g[i+j]=min(g[i+j],f[u][i]+f[v][j]);
		}	
		sz[u]+=sz[v];
		for (int i=1;i<=sz[u];++i) 
			f[u][i]=g[i];
	}
	if (sz[u]>=p)
		ans=min(ans,f[u][p]+(u==1?0:1));
}
int main() {
	cin>>n>>p;
	for (int i=1;i<n;++i){
		cin>>s>>t;
		e[s].push_back(t);
	}
	ans=0x3f3f3f3f;
	dfs(1);
	cout<<ans;
}