#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
#define pb push_back
#define all(x) (x).begin(), (x).end()
#define sz(x) (int) (x).size()
#define endl '\n'
int main()
{
cin.tie(0) -> sync_with_stdio(0);
int n, q;
cin >> n >> q;
for(int i = 0;i < n-1;i++)
{
int u, v;
cin >> u >> v;
}
cout << n-1 << endl;
while(q--)
{
int d;
cin >> d;
vector<int> s(d);
for(auto& i : s) cin >> i;
if(d&1) {cout << -1 << endl;continue;}
sort(all(s));
int ans=n-1;
for(int i = 0;i < d-1;i++) ans+=abs(s[i+1]-s[i])+2;
cout << ans;
}
}
