#include <bits/stdc++.h>
#define N 700011
#define pii pair<int,int>
#define s1 first
#define s2 second
#define ll long long
using namespace std;
int n,m,q,a[N];
vector<int> G[N];int dfn[N],siz[N],dep[N],h[N],st[21][N],rk[N],clk,lg[N];
void dfs(int u,int F)
{
	dfn[u]=++clk;dep[u]=dep[F]+1;rk[clk]=u;h[clk]=u;siz[u]=1;
	for(int v:G[u])if(v^F)
	{
		dfs(v,u);
		h[clk]=u;siz[u]+=siz[v];
	}
}
int lca(int x,int y)
{
	if(x==y)return x;
	if(rk[x]>rk[y])swap(x,y);
	int logl=lg[rk[y]-rk[x]];
	int u1=st[logl][rk[x]],u2=st[logl][rk[y]-(1<<logl)];
	return dep[u1]<dep[u2]?u1:u2;
}
int rg[21][N];
int qlca(int l,int r)
{
	if(l==r)return l;
	int logl=lg[r-l];
	int u1=rg[logl][l],u2=rg[logl][r-(1<<logl)];
	return lca(u1,u2);
}
struct kueri{int x,y,k,id;};
vector<kueri> vk[N];
struct point{int x,id,w;};
vector<point> vv;
int sum[N];
int ql[N],qr[N];
ll ans[N];
bool insub(int u,int v){return dfn[u]<=dfn[v]&&dfn[v]<dfn[u]+siz[u];}
void push(point p)
{
	vv.push_back(p);
	sum[vv.size()-1]=(vv.size()>=2?sum[vv.size()-2]:0)+p.w;
}
int main()
{
	scanf("%d%d%d",&n,&m,&q);
	for(int i=1;i<n;++i){int u,v;scanf("%d%d",&u,&v);G[u].push_back(v);G[v].push_back(u);}
	dfs(1,0);
	for(int i=1;i<n;++i)st[0][i]=h[i];
	for(int i=1;i<=20;++i)
	{
		for(int j=1;j+(1<<i)-1<n;++j)
		{
			int u1=st[i-1][j],u2=st[i-1][j+(1<<i-1)];
			st[i][j]=dep[u1]<dep[u2]?u1:u2;
		}
	}
	lg[0]=-1;for(int i=1;i<N;++i)lg[i]=lg[i>>1]+1;
	for(int i=1;i<=m;++i)scanf("%d",a+i);
	for(int i=1;i<m;++i)rg[0][i]=lca(a[i],a[i+1]);
	for(int i=1;i<=20;++i)
	{
		for(int j=1;j+(1<<i)-1<m;++j)
		{
			int u1=rg[i-1][j],u2=rg[i-1][j+(1<<i-1)];
			rg[i][j]=lca(u1,u2);
		}
	}
	for(int i=1;i<=q;++i)
	{
		int k;scanf("%d",&k);
		for(int j=1;j<=k;++j)scanf("%d%d",ql+j,qr+j);
		int x=-1;
		for(int j=1;j<=k;++j)
		{
			vk[ql[j]].push_back({ql[j],qr[j],x,i});
			// printf("([%d,%d],x:%d) ",ql[j],qr[j],x);
			if(~x)x=lca(x,qlca(ql[j],qr[j]));
			else x=qlca(ql[j],qr[j]);
		}
		// putchar(10);
	}
	for(int i=m;i;--i)
	{
		int x=a[i];
		while(!vv.empty()&&!insub(vv.back().x,a[i]))vv.pop_back();
		push({x,i,1});
		// printf("i:%d vv:",i);for(point x:vv)printf("{%d,%d,%d} ",x.x,x.id,x.w);putchar(10);
		for(kueri k:vk[i])
		{
			int L=0,R=(int)vv.size()-1,rb=-1;
			if(~k.k)
			{
				while(L<=R)
				{
					int M=L+R>>1;
					if(insub(vv[M].x,k.k))rb=M,L=M+1;else R=M-1;
				}
			}
			else rb=(int)vv.size()-1;
			L=0,R=(int)vv.size()-1;int lb=vv.size();
			while(L<=R)
			{
				int M=L+R>>1;
				if(vv[M].id<=k.y)lb=M,R=M-1;else L=M+1;
			}
			// printf("query([%d,%d],x:%d) lb:%d rb:%d\n",k.x,k.y,k.k,lb,rb);
			ans[k.id]+=max(0,sum[rb]-(lb>0?sum[lb-1]:0));
		}
	}
	for(int i=1;i<=q;++i)printf("%lld\n",ans[i]);
	fclose(stdin);fclose(stdout);return 0;
}