#include<bits/stdc++.h>
#define pb push_back
#define endl '\n'
using namespace std;
const long long maxn = 3e5 + 10;
void speed()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
}
long long n, m, q;
vector < pair < long long , long long > > g[maxn];
vector < pair < long long , long long > > u;
long long a[maxn], b[maxn];
struct persistent_sgt
{
struct node
{
long long val, cnt, l, r;
node()
{
val = 0;
cnt = 0;
l = 0;
r = 0;
};
node(long long _val, long long _cnt, long long _l, long long _r)
{
val = _val;
cnt = _cnt;
l = _l;
r = _r;
}
};
long long n;
vector < node > t;
long long tmr = 1;
node join (long long l, long long r)
{
return node(t[l].val + t[r].val, t[l].cnt + t[r].cnt, l, r);
}
long long build(long long i, long long l, long long r)
{
if(l == r)
{
t[tmr] = node(0, 0, 0, 0);
tmr ++;
return tmr - 1;
}
long long mid = (l + r)/2;
t[tmr] = join(build(2*i, l, mid), build(2*i+1, mid+1, r));
tmr ++;
return tmr - 1;
}
long long upd(long long i, long long l, long long r, long long upos, long long uval)
{
if(l == r)
{
t[tmr] = node(t[i].val + uval, t[i].cnt + 1, 0, 0);
tmr ++;
return tmr - 1;
}
long long mid = (l + r)/2;
if(upos <= mid)t[tmr] = join(upd(t[i].l, l, mid, upos, uval), t[i].r);
else t[tmr] = join(t[i].l, upd(t[i].r, mid+1, r, upos, uval));
tmr ++;
return tmr - 1;
}
long long query(long long i, long long l, long long r, long long ql, long long qr)
{
if(qr < l || ql > r)return 0;
if(ql <= l && r <= qr)return t[i].val;
long long mid = (l + r)/2;
return query(t[i].l, l, mid, ql, qr) + query(t[i].r, mid+1, r, ql, qr);
}
long long query_cnt(long long i, long long l, long long r, long long ql, long long qr)
{
if(qr < l || ql > r)return 0;
if(ql <= l && r <= qr)return t[i].cnt;
long long mid = (l + r)/2;
return query_cnt(t[i].l, l, mid, ql, qr) + query_cnt(t[i].r, mid+1, r, ql, qr);
}
void prep(long long sz, long long maxt)
{
n = sz;
t.resize(maxt);
}
long long run_build()
{
return build(1, 1, n);
}
long long run_upd(long long root, long long upos, long long uval)
{
return upd(root, 1, n, upos, uval);
}
long long run_query(long long root, long long ql, long long qr)
{
return query(root, 1, n, ql, qr);
}
long long run_query_cnt(long long root, long long ql, long long qr)
{
return query_cnt(root, 1, n, ql, qr);
}
};
persistent_sgt p;
vector < long long > roots;
int main()
{
speed();
cin >> n >> m >> q;
for (long long i = 1; i < n; ++ i)
{
long long from, to;
cin >> from >> to;
a[i] = from;
b[i] = to;
g[from].pb({to, i}); /// ?
g[to].pb({from, i});
}
for (long long i = 1; i <= m; ++ i)
{
long long road, silver;
cin >> road >> silver;
u.pb(make_pair(silver, road));
}
p.prep(n, 40*n);
roots.pb(p.run_build());
long long last = roots.back();
sort(u.begin(), u.end());
for (auto &[silver, road]: u)
{
long long setpos = max(a[road], b[road]);
long long nr = p.run_upd(last, setpos, silver);
roots.pb(nr);
last = nr;
}
assert(roots.size() == m + 1);
//cout << "last is " << last << endl;
while(q --)
{
long long si, ti, xi, yi;
cin >> si >> ti >> xi >> yi;
if(si > ti)swap(si, ti);
long long tot = p.run_query_cnt(last, si+1, ti);
long long l = 0, r = roots.size()-1, mid, ans = 0; /// tyrsq nai posledniq moment v koito sumata v range-a mi e <= yi
while(l <= r)
{
mid = (l + r)/2;
long long sum = p.run_query(roots[mid], si+1, ti);
if(sum <= yi)
{
l = mid + 1;
ans = p.run_query_cnt(roots[mid], si+1, ti);
}
else r = mid - 1;
}
// cout << tot << " " << ans << endl;
if(xi < (tot-ans))cout << -1 << endl;
else cout << xi - (tot - ans) << endl;
}
return 0;
}
