#include <bits/stdc++.h>
using namespace std;
#define int long long
#define pii pair<int,int>
#define pb push_back
#define all(x) x.begin(),x.end()
#define ff first
#define ss second
signed main(){
ios_base::sync_with_stdio(false);cin.tie(0);
int n, m, q;cin>>n>>m>>q;
vector<vector<int>> g(n+1);
vector<pii> e(n+1);
for(int i=1; i<=n-1; i++){
int a, b;cin>>a>>b;
g[a].pb(b);
g[b].pb(a);
e[i]={a, b};
}
vector<int> spots(m+1);
for(int i=1; i<=m; i++) cin>>spots[i];
while(q--){
int l, r;cin>>l>>r;
int mini=1e9, maxi=0;
for(int i=l; i<=r; i++){
mini=min(mini, spots[i]);
maxi=max(maxi, spots[i]);
}
cout<<maxi-mini+1<<'\n';
}
}
