#pragma comment(linker,"/STACK:1024000000,1024000000")
#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<cmath>
#include<queue>
#include<vector>
#include<set>
#include<stack>
#include<map>
#include<ctime>
#include<bitset>
#define LL long long
#define maxn 100010
#define INF 0x3f3f3f3f
using namespace std;

int head[maxn],to[maxn*2],next1[maxn*2] ;
int top,cnt[maxn],len ;
int f[maxn];
bool vi[maxn] ;

void Unit(int u,int v)
{
    next1[top] = head[u] ;to[top]=v;
    head[u]=top++;
}

void find1( int u ,int fa )
{
    f[u] = 0 ;
    cnt[u] = 1 ;
    int v ;
    for( int i = head[u] ; i != -1; i = next1[i])
    {
         v = to[i] ;
        if(v==fa||vi[v]) continue ;
        find1(v,u) ;
        cnt[u] += cnt[v] ;
        f[u] = max(cnt[v],f[u]) ;
    }
}
int minn,k,n,MAX ;
void find_root1( int u ,int fa,int &root,int sum)
{
    int tmp = max(sum-cnt[u],f[u]) ;
    if(tmp < minn)
    {
        minn = tmp ;
        root = u ;
    }
    int v;
    for( int i = head[u] ; i != -1; i = next1[i])
    {
        v = to[i] ;
        if(v==fa||vi[v]) continue ;
        find_root1(v,u,root,sum) ;
    }
}

int get_root( int u )
{
    find1(u,-1) ;
    int sum = cnt[u] ;
    int root = u ;
    minn = n ;
    find_root1(u,-1,root,sum) ;
    return root ;
}
int que[maxn],tt;
int num[maxn],ans[maxn] ;
vector<int>vec;

void find(int len)
{
    for(int i = 1 ; i <= MAX ;i++)if(i+len<=MAX)
    {
        ans[i+len] += num[i] ;
    }
}
void dfs(int u,int fa,int len1)
{
    int v ;
    ans[len1]++;
    vec.push_back(len1);
    find(len1) ;
    for( int i = head[u] ; i != -1; i = next1[i])
    {
        v = to[i] ;
        if(v==fa||vi[v]||len1+1>MAX) continue ;
        dfs(v,u,len1+1) ;
    }
}
void count(int u)
{
    int v ,j ;
    //memset(num,0,sizeof(num));
    tt=0;
    for(int i = head[u] ; i != -1; i = next1[i])
    {
        v = to[i] ;
        if(vi[v]) continue ;
        len=0;
        vec.clear();
        dfs(v,u,1);
        for( j = 0 ; j < vec.size();j++)
        {
            if(!num[vec[j]])que[tt++]=vec[j];
             num[vec[j]]++;
        }
    }
    for(int i = 0 ; i < tt;i++)
        num[que[i]]=0;
}
void solve(int u)
{
    int root=get_root(u);
    vi[root]=true;
    count(root);
    for(int i = head[root] ; i != -1; i = next1[i])
    {
        int v = to[i] ;
        if(vi[v]) continue ;
        solve(v) ;
    }
}
void init()
{
    len = 0 ;
    memset(vi,0,sizeof(vi)) ;
    top=0;
    memset(head,-1,sizeof(head)) ;
    memset(num,0,sizeof(num)) ;
    memset(ans,0,sizeof(ans)) ;
}
int main()
{
    int i ,j ,m ;
    int T,u,v;
    // freopen("in.txt","r",stdin);
    // freopen("out.txt","w",stdout);
    cin >> T ;
    while(T--)
    {
        scanf("%d%d",&n,&k) ;
        MAX=min(k/n+70,k);
        init();
        for( i = 1 ; i < n ;i++)
        {
            scanf("%d%d",&u,&v);
            Unit(u,v) ;
            Unit(v,u) ;
        }
        solve(1);
        LL sum=0;
        for( i = 1 ; i <= MAX ;i++)
        {
            if(ans[i]>=k){
                sum += (LL)k*i ;
                break;
            }
            k -= ans[i] ;
            sum += (LL)ans[i]*i ;
        }
        printf("%I64d\n",sum) ;
    }
    return 0 ;
}