#include<bits/stdc++.h>
using namespace std;
const int N =

#include<bits/stdc++.h>
using namespace std;
const int N = 2e5+10; 
vector<int>G[N];
int n,k,res[N],ans;//res:标记该子树是否有剩余节点未连接 
void dfs(int x,int xfa)//遍历 
{
	for(int y:G[x])if(y!=xfa)
	{
		dfs(y,x);
        res[x]+=res[y];
	}
    res[x]=min(res[x],2*k);
    ans+=res[x]/2,res[x]%=2;
}
int main()
{
	scanf("%d%d",&n,&k);
	for(int i=1,x,y;i<=n-1;i++)
	{
		scanf("%d%d",&x,&y);
		G[x].push_back(y);
        G[y].push_back(x);
	}
    memset(res,0,sizeof(res));
    for(int i=1;i<=n;i++) if(G[i].size()==1)res[i]=1;
    ans=0;
    dfs(1,0);
	printf("%d\n",ans);
	return 0;
}