#pragma GCC target("avx2")
#pragma GCC optimization("O3")
#pragma GCC optimization("unroll-loops")
#include<bits/stdc++.h>
#include "highway.h"
#define rc(x) return cout<<x<<endl,0
#define pb push_back
#define mkp make_pair
#define in insert
#define er erase
#define fd find
#define fr first
#define sc second
typedef long long ll;
typedef long double ld;
const ll INF=0x3f3f3f3f3f3f3f3f;
const ll llinf=(1LL<<62);
const int inf=(1<<30);
const ll nmax=1e5+50;
const int mod=1e9+7;
using namespace std;
int n,i,x,y,viz[nmax],l,r,mid,ub,lb;
ll d,d1,f,s;
vector<pair<int,int> >ord,a[nmax],nw;
vector<int>vc;
void dfs(int x,int y)
{
if(viz[x])return;
if(y!=-1)ord.pb(mkp(x,y));
viz[x]=1;
for(int i=0;i<a[x].size();i++)dfs(a[x][i].fr,a[x][i].sc);
}
void dfs1(int x,int l,int y)
{
if(viz[x])return;
viz[x]=1;
if(l==d/f)nw.pb(mkp(x,y));
for(int i=0;i<a[x].size();i++)dfs1(a[x][i].fr,l+1,a[x][i].sc);
}
/*int ask()
{
ll x;
for(int i=0;i<n-1;i++)cout<<vc[i]<<" ";
cout<<endl;
cin>>x;
return x;
}*/
int ok(int x)
{
int i;
for(i=0;i<x;i++)vc[ord[i].sc]=1;
for(;i<n-1;i++)vc[ord[i].sc]=0;
return (ask(vc)<d1);
}
int ok1(int x)
{
int i;
for(i=0;i<n-1;i++)vc[i]=0;
for(i=0;i<x;i++)vc[nw[i].sc]=1;
return (ask(vc)==d);
}
void find_pair(int N,vector<int>U,vector<int>V,int A,int B)
{
n=N;
for(i=0;i<n-1;i++)
{
x=U[i],y=V[i];
a[x].pb(mkp(y,i));
a[y].pb(mkp(x,i));
}
f=A,s=B;
dfs(1,-1);
for(i=0;i<n-1;i++)vc.pb(0);
d=ask(vc);
d1=(d/f)*s;
l=1,r=n-1;
while(l<=r)
{
mid=(l+r)/2;
if(ok(mid))l=mid+1;
else ub=mid,r=mid-1;
}
memset(viz,0,sizeof(viz));
dfs1(ord[ub-1].fr,0,-1);
l=1,r=(int)nw.size();
while(l<=r)
{
mid=(l+r)/2;
if(ok1(mid))l=mid+1;
else lb=mid,r=mid-1;
}
answer(nw[lb-1].fr,ord[ub-1].fr);
}
/*int main()
{
//freopen("sol.in","r",stdin);
//freopen("sol.out","w",stdout);
//mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
ios_base::sync_with_stdio(false);cin.tie(0);cerr.tie(0);cout.tie(0);
cin>>n;
for(i=1;i<n;i++)
{
cin>>x>>y;
a[x].pb(mkp(y,i-1));
a[y].pb(mkp(x,i-1));
}
cin>>f>>s;
dfs(1,-1);
cout<<endl;
//for(i=0;i<n-1;i++)cout<<ord[i].fr<<" "<<ord[i].sc<<endl;
for(i=0;i<n-1;i++)vc.pb(0);
d=ask();
d1=(d/f)*s;
l=1,r=n-1;
while(l<=r)
{
mid=(l+r)/2;
if(ok(mid))l=mid+1;
else ub=mid,r=mid-1;
}
memset(viz,0,sizeof(viz));
dfs1(ord[ub-1].fr,0,-1);
//for(i=0;i<nw.size();i++)cout<<nw[i].fr<<" "<<nw[i].sc<<endl;
l=1,r=(int)nw.size();
while(l<=r)
{
mid=(l+r)/2;
if(ok1(mid))l=mid+1;
else lb=mid,r=mid-1;
}
//cout<<lb<<" "<<ub<<endl;
cout<<nw[lb-1].fr<<" "<<ord[ub-1].fr<<endl;
return 0;
}*/
/*
9
1 2
2 3
2 4
1 6
1 5
8 9
6 7
6 8
2 5
*/
