#include<bits/stdc++.h>
using namespace std;
#define ll long long
ll n,m,q,uu[100005],vv[100005],p[100005],child[100005],h[100005],par[100005],in[100005],out[100005],chainhead[100005],chainid[100005],timehld,timedfs,f[400005],l[100005],r[100005],dd,s[100005],t[100005],x[100005],y[100005],vc[100005],pp[100005];
vector<ll>a[100005];
vector<ll>que[100005];
pair<ll,ll>c[100005];
void dfsmake(ll x,ll pa)
{
child[x]=1;
for(auto it:a[x])
if(it!=pa)
{
h[it]=h[x]+1;
par[it]=x;
dfsmake(it,x);
child[x]+=child[it];
}
}
void dfshld(ll x,ll pa)
{
if(chainhead[timehld]==0)
chainhead[timehld]=x;
chainid[x]=timehld;
timedfs++;
in[x]=timedfs;
ll heavy=0;
for(auto it:a[x])
if(it!=pa)
if(heavy==0||child[it]>child[heavy])heavy=it;
if(heavy!=0)dfshld(heavy,x);
for(auto it:a[x])
if(it!=pa&&it!=heavy)
{
timehld++;
dfshld(it,x);
}
out[x]=timedfs;
return;
}
ll getlca(ll x,ll y)
{
while(chainid[x]!=chainid[y])
{
if(chainid[x]>chainid[y])
x=par[chainhead[chainid[x]]];
else
y=par[chainhead[chainid[y]]];
}
if(h[x]<h[y])return x;
return y;
}
void update(ll id,ll l,ll r,ll i,ll v)
{
if(i<l||i>r)
return;
if(l==r)
{
f[id]+=v;
return;
}
ll mid=(l+r)/2;
update(id*2,l,mid,i,v);
update(id*2+1,mid+1,r,i,v);
f[id]=f[id*2]+f[id*2+1];
}
ll getsum(ll id,ll l,ll r,ll u,ll v)
{
if(l>r)return 0;
if(v<l||r<u)return 0;
if(u<=l&&v>=r)return f[id];
ll mid=(l+r)/2;
return getsum(id*2,l,mid,u,v)+getsum(id*2+1,mid+1,r,u,v);
}
ll getquery(ll u,ll v)
{
ll lca=getlca(u,v);
ll ans=0;
while(chainid[u]!=chainid[lca])
{
ans+=getsum(1,1,n,in[chainhead[chainid[u]]],in[u]);
u=par[chainhead[chainid[u]]];
}
while(chainid[v]!=chainid[lca])
{
ans+=getsum(1,1,n,in[chainhead[chainid[v]]],in[v]);
v=par[chainhead[chainid[v]]];
}
if(h[u]<h[v])
ans+=getsum(1,1,n,in[u]+1,in[v]);
else
ans+=getsum(1,1,n,in[v]+1,in[u]);
return ans;
}
void dfssl(ll x,ll pa)
{
for(ll it:a[x])
if(it!=pa)
{
pp[it]+=pp[x];
dfssl(it,x);
}
}
int main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);cout.tie(0);
cin>>n>>m>>q;
for(int i=1;i<n;i++)
{
cin>>uu[i]>>vv[i];
a[uu[i]].push_back(vv[i]);
a[vv[i]].push_back(uu[i]);
}
dfsmake(1,0);
dfshld(1,0);
for(int i=1;i<=m;i++)
{
cin>>c[i].second>>c[i].first;
c[i].second=max(in[vv[c[i].second]],in[uu[c[i].second]]);
}
sort(c+1,c+m+1);
for(int i=1;i<=q;i++)
{
cin>>s[i]>>t[i]>>x[i]>>y[i];
l[i]=1;
r[i]=m;
vc[i]=0;
}
while(1)
{
dd=0;
for(int i=1;i<=q;i++)
if(l[i]<=r[i])
{
que[(l[i]+r[i])/2].push_back(i);
dd++;
}
if(dd==0)
break;
for(int i=1;i<=4*n;i++)
f[i]=0;
for(ll i=1;i<=m;i++)
{
update(1,1,n,c[i].second,c[i].first);
for(ll it:que[i])
{
dd=getquery(s[it],t[it]);
// cout<<s[it]<<" "<<t[it]<<'\n';
// cout<<it<<" "<<i<<" "<<dd<<'\n';
if(y[it]>=dd)
{
l[it]=i+1;
vc[it]=max(vc[it],i);
}
else
r[it]=i-1;
}
que[i].clear();
}
}
for(int i=1;i<=q;i++)
que[vc[i]].push_back(i);
for(int i=1;i<=4*n;i++)
f[i]=0;
for(int i=1;i<=m;i++)
{
update(1,1,n,c[i].second,1);
for(ll it:que[i])
vc[it]=getquery(s[it],t[it]);
que[i].clear();
}
for(int i=1;i<=q;i++)
{
dd=getquery(s[i],t[i]);
dd-=vc[i];
if(x[i]>=dd)
cout<<x[i]-dd<<'\n';
else
cout<<-1<<'\n';
}
return 0;
}
