#include <bits/stdc++.h>
#define F first
#define S second
#define pb push_back
#define ppb pop_back
#define ep insert
#define endl '\n'
#define elif else if
#define pow pwr
#define sqrt sqrtt
#define int long long
#define ll long long
typedef unsigned long long ull;
using namespace std;
const int N=1e5+5;
int n,m,q,b[N],stmn[20][N],stmx[20][N],lg[N];
vector<int> adj[N];
void build(){
for (int i=1;i<=m;i++) stmn[0][i]=stmx[0][i]=b[i];
for (int i=1;i<20;i++){
for (int j=1;j+(1<<i)<=m+1;j++){
stmx[i][j]=max(stmx[i-1][j],stmx[i-1][j+(1<<(i-1))]);
stmn[i][j]=min(stmn[i-1][j],stmn[i-1][j+(1<<(i-1))]);
}
}
return;
}
int query(int l,int r){
int i=lg[r-l+1];
return max(stmx[i][l],stmx[i][r-(1<<i)+1])-min(stmn[i][l],stmn[i][r-(1<<i)+1])+1;
}
int32_t main(){
ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
for (int i=2;i<N;i++) lg[i]=lg[i/2]+1;
cin>>n>>m>>q;
for (int i=1;i<n;i++){
int x,y;
cin>>x>>y;
adj[x].pb(y);
adj[y].pb(x);
}
for (int i=1;i<=m;i++) cin>>b[i];
build();
while (q--){
int l,r;
cin>>l>>r;
cout<<query(l,r)<<endl;
}
return 0;
}
