#include<bits/stdc++.h>
using namespace std;
#define int long long
const int INF = 1e18;
int n,m,q;
int aib[100005][2];
int qry(int p, int c)
{
int aux=0;
for(int i=p;i>0;i-=(i&(-i)))
aux += aib[i][c];
return aux;
}
void upd(int p, int val, int c)
{
for(int i=p;i<=n;i+=(i&(-i)))
aib[i][c] += val;
}
vector<int> con[100005];
pair<int,int> edges[100005];
int tin[100005],tout[100005],timer;
int parent[100005];
vector<pair<int,int>> obstacole;
pair<int,int> drum[100005],bani[100005];
int lc[100005];
int anc[100005][17];
int rez[100005];
void dfs_init(int nod)
{
tin[nod]=++timer;
for(auto adj:con[nod])
{
if(adj!=parent[nod])
{
parent[adj]=nod;
dfs_init(adj);
}
}
tout[nod]=timer;
}
bool isanc(int x, int y)
{
return (tin[x]<=tin[y] && tout[x]>=tout[y]);
}
int lca(int x, int y)
{
if(isanc(x,y))
return x;
if(isanc(y,x))
return y;
for(int p=16;p>=0;p--)
if(!isanc(anc[x][p],y))
x = anc[x][p];
return anc[x][0];
}
int poz;
void cautare_binara(int st, int dr, vector<int> ids)
{
if(st>dr || ids.empty())
return;
int mij=(st+dr)/2;
while(poz<mij)
{
poz++;
upd(tin[obstacole[poz].second], obstacole[poz].first, 0);
upd(tout[obstacole[poz].second]+1, -obstacole[poz].first, 0);
upd(tin[obstacole[poz].second], -1, 1);
upd(tout[obstacole[poz].second]+1, +1, 1);
}
while(poz>mij)
{
upd(tin[obstacole[poz].second], -obstacole[poz].first, 0);
upd(tout[obstacole[poz].second]+1, obstacole[poz].first, 0);
upd(tin[obstacole[poz].second], +1, 1);
upd(tout[obstacole[poz].second]+1, -1, 1);
poz--;
}
vector<int> tole,tori;
for(auto x:ids)
{
int aux0 = qry(tin[drum[x].first],0) + qry(tin[drum[x].second],0) - 2*qry(tin[lc[x]],0);
int aux1 = qry(tin[drum[x].first],1) + qry(tin[drum[x].second],1) - 2*qry(tin[lc[x]],1);
//cout<<aux0<<" aux0\n";
if(aux0 <= bani[x].second)
{
rez[x] = min(rez[x], aux1);
tori.push_back(x);
}
else
tole.push_back(x);
}
if(st<dr)
{
cautare_binara(st,mij,tole);
cautare_binara(mij+1,dr,tori);
}
}
signed main()
{
cin>>n>>m>>q;
int a,b;
for(int i=1;i<n;i++)
{
cin>>a>>b;
edges[i] = {a,b};
con[a].push_back(b);
con[b].push_back(a);
}
dfs_init(1);
for(int i=1;i<n;i++)
if(parent[edges[i].first]==edges[i].second)
swap(edges[i].first, edges[i].second);
for(int i=1;i<=n;i++)
anc[i][0]=parent[i];
anc[1][0]=1;
for(int p=1;p<17;p++)
for(int i=1;i<=n;i++)
anc[i][p] = anc[anc[i][p-1]][p-1];
for(int i=1;i<=m;i++)
{
cin>>a>>b;
obstacole.push_back({b,edges[a].second});
upd(tin[edges[a].second], +1, 1);
upd(tout[edges[a].second]+1, -1, 1);
}
sort(obstacole.begin(),obstacole.end());
vector<int> ids;
for(int i=1;i<=q;i++)
{
cin>>drum[i].first>>drum[i].second>>bani[i].first>>bani[i].second;
lc[i] = lca(drum[i].first, drum[i].second);
ids.push_back(i);
rez[i] = qry(tin[drum[i].first],1) + qry(tin[drum[i].second],1) - 2*qry(tin[lc[i]],1);
}
poz=-1;
cautare_binara(0,m-1,ids);
for(int i=1;i<=q;i++)
{
if(rez[i] > bani[i].first)
cout<<-1<<"\n";
else
cout<<bani[i].first-rez[i]<<"\n";
}
return 0;
}
