/*
Bismillahir rahmanir rahim
Allahu akbar
Alhamdulillah
Subhanallah
Rabbi a’inni wa-la tu’in ‘alayya,
wa-nsurni wa-la tansur ‘alayya,
wa-mkur-li wa-la tamkur alayya,
wa-hdini wa-yassir-il-huda ilayya,
wa-nsurni ‘ala man bagha ‘alayya
Ya Hayyu Ya Qayyum,
birahmatika astaghitsu,
aslih li sha'ni kullahu,
wa la takilni ila nafsi tarfata ‘aini
*/
#include <bits/stdc++.h>
#define ll long long
#define int long long
#define pb(x) push_back(x)
#define sor(x) sort(x.begin(), x.end())
#define rsor(x) sort(x.rbegin(), x.rend())
#define yes cout << "YES\n";
#define no cout << "NO\n";
#pragma pack(1)
using namespace std;
const int N = 2e5 + 55;
const int MOD = 1e9 + 7;
const bool T = false;
ll bp(ll a, ll n)
{
if(n == 0)
{
return 1;
}
if (n & 1)
{
return bp(a, n - 1) * a % MOD;
}
else
{
ll temp = bp(a, n / 2);
return temp * temp % MOD;
}
}
vector<ll> g[N];
void hippopotomonstrosesquipedaliophobia()
{
ll n, q;
cin >> n >> q;
bool f1, f2;
f1 = f2 = 1;
for (int i = 1; i < n; i++)
{
ll x, y;
cin >> x >> y;
g[x].pb(y);
g[y].pb(x);
if(x != y + 1 and y != x + 1)
{
f1 = 0;
}
if(x != 1 and y != 1)
{
f2 = 0;
}
}
if(f1 == 1)
{
for (int i = 1; i <= q; i++)
{
ll d;
cin >> d;
ll x = 2;
ll dist = n - 1;
vector<ll> vc;
for (int j = 0; j < d; j++)
{
ll u;
cin >> u;
x++;
vc.pb(u);
}
if(x % 2 == 1)
{
cout << -1 << '\n';
}
else
{
sor(vc);
for (int i = 0; i < vc.size(); i+=2)
{
dist += abs(vc[i] - vc[i + 1]);
}
}
}
return;
}
if(f2 == 1)
{
for (int i = 0; i < q; i++)
{
ll d;
ll as = n - 1;
cin >> d;
for (int j = 0; j < d; j++)
{
ll x;
cin >> x;
if(x == 1)
{
as++;
}
}
if(as % 2 == 1)
{
cout << -1 << '\n';
}
else
{
cout << (as / 2) << '\n';
}
}
return;
}
for (int i = 1; i <= q; i++)
{
ll d;
cin >> d;
for (int j = 0; j < d; j++)
{
ll x;
cin >> x;
}
}
}
signed main(void)
{
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int time = 1;
if (T)
{
cin >> time;
}
while (time--)
{
hippopotomonstrosesquipedaliophobia();
}
return 0;
}
