#include <bits/stdc++.h>
using namespace std;
#define int long long
const int INF = 1e18;
struct segtree{
vector<int> tree;
segtree():tree(262144){}
void update(int k,int x){
k+=131072;
tree[k]=x;
while(k/=2){
tree[k]=min(tree[2*k],tree[2*k+1]);
}
}
int get(int a,int b){
a+=131072;b+=131072;
int ans = INF;
while(a<=b){
if(a&1)ans=min(ans,tree[a++]);
if(b%2 == 0)ans=min(ans,tree[b--]);
a/=2;b/=2;
}
return ans;
}
};
int32_t main(){
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
int n,m,q;
cin >> n >> m >> q;
vector<vector<int>> adj(n+1);
for(int i=1;i<n;i++){
int a,b;cin>>a>>b;
adj[a].emplace_back(b);
adj[b].emplace_back(a);
}
int tim = 0;
vector<int> newidx(n+1);
function<void(int,int)> dfs = [&](int x,int par){
newidx[x]=++tim;
for(int&i:adj[x])if(i!=par)dfs(i,x);
};
dfs(1,0);
vector<vector<int>> newadj(n+1);
for(int i=1;i<=n;i++)newadj[newidx[i]]=adj[i];
for(int i=1;i<=n;i++){
for(int&x:newadj[i])x=newidx[x];
}
swap(newadj,adj);
vector<vector<int>> lift(n+1,vector<int>(17));
vector<int> depth(n+1);
function<void(int,int,int)> dfs2 = [&](int x,int par,int dep){
lift[x][0]=par;
depth[x]=dep;
for(int&i:adj[x])if(i!=par)dfs2(i,x,dep+1);
};
dfs2(1,0,1);
for(int bit=1;bit<17;bit++){
for(int i=1;i<=n;i++){
lift[i][bit] = lift[lift[i][bit-1]][bit-1];
}
}
auto lca = [&](int a,int b){
if(depth[a]>depth[b])swap(a,b);
int tar = depth[b]-depth[a];
for(int bit=0;bit<17;bit++)if(tar&(1<<bit))b=lift[b][bit];
if(a==b)return a;
for(int bit=16;bit>=0;bit--){
if(lift[a][bit]!=lift[b][bit]){
a = lift[a][bit];
b = lift[b][bit];
}
}
return lift[a][0];
};
vector<int> checkpoints(m+1);
for(int i=1;i<=m;i++){
int x;cin>>x;
checkpoints[i]=newidx[x];
}
for(int i=1;i<=q;i++){
int l,r;
cin >> l >> r;
vector<int> buffer;
for(int x=l;x<=r;x++)buffer.emplace_back(checkpoints[x]);
sort(buffer.begin(),buffer.end());
int lcaall = buffer[0];
for(int&x:buffer)lcaall=lca(lcaall,x);
int ans = depth[buffer[0]]-depth[lcaall]+1;
for(int x=1;x<buffer.size();x++){
ans+=depth[buffer[x]]-depth[lca(buffer[x],buffer[x-1])];
}
cout << ans << '\n';
}
}
