#include<bits/stdc++.h>
using namespace std;const int maxn = 3e4+5;
int n,m;
int hd[maxn], nx[maxn<<1], to[maxn<<1], dam[maxn<<1], len[maxn<<1], ec;inline void add(int u,int v,int D,int L)
{to[ec] = v;dam[ec] = D;len[ec] = L;nx[ec] = hd[u];hd[u] = ec++;
}int root, best;
int ct[maxn];
//best = n
void GetBaryCenter(int u,int f)
{ct[u] = 1;int Mx = 0;for(int i = hd[u]; ~i; i = nx[i]){if(to[i] != f){GetBaryCenter(to[i], u);ct[u] += ct[to[i]];Mx = max(Mx,ct[to[i]]);}}Mx = max(Mx,n-ct[u]);if(Mx < best){best = Mx;root = u;}
}#define MP make_pair
#define fi first
#define se second
int C[maxn], L[maxn];map<int,int> mp;
map<int,int>::iterator it;int ans;
int path[maxn];
int pre[maxn], dfs_clk;
//dfs_clk = 0, ans = 0;
void dfs(int u = root,int f = 0)
{path[dfs_clk] = u;pre[u] = dfs_clk++;C[u] = 0; L[u] = 0;for(int i = hd[u]; ~i; i = nx[i]){if(to[i] != f){int v = to[i];dfs(v,u);for(int j = pre[v]; j < dfs_clk ; j++){int x = path[j];C[x] += dam[i];L[x] += len[i];}}}//子树都访问完里以后统一处理以保证互不干扰，这样mp就可以设置为全局变量
    mp.clear();for(int i = hd[u]; ~i; i = nx[i]){int nex = nx[i];int lim = ~nex? pre[to[nex]] : dfs_clk;if(to[i] != f){int v = to[i];for(int j = pre[v]; j < lim ; j++){int x = path[j];if(C[x] <= m){ans = max(ans,L[x]);it = mp.upper_bound(m-C[x]);//找到一个key <= C[x]if(it != mp.begin()){ans = max(ans,(--it)->second+L[x]);}}}for(int j = pre[v]; j < lim ; j++){int x = path[j];if(C[x] <= m){it = mp.lower_bound(C[x]);bool swc = false;if(it == mp.begin() || (swc = true , L[x] > (--it)->se) ){if(swc) it++;while(it != mp.end() && it->se <= L[x]) mp.erase(it++);if(it == mp.end() || it->fi > C[x]) {//lower_bound可能使得it指向key == C[x] 而 val >= L[x]
                            mp.insert(MP(C[x],L[x]));}}}}}}
}//#define LOCAL
int main()
{
#ifdef LOCALfreopen("in.txt","r",stdin);
#endifint T, ks = 0; cin>>T;while(T--){scanf("%d%d",&n,&m);memset(hd+1,-1,sizeof(int)*n); ec = 0;for(int i = n; --i;){int a,b,D,L; scanf("%d%d%d%d",&a,&b,&D,&L);add(a,b,D,L); add(b,a,D,L);}best = n+1;GetBaryCenter(1,0);dfs_clk = ans = 0;dfs();printf("Case %d: %d\n",++ks,ans);}return 0;
}