#include<bits/stdc++.h>
using namespace std;
vector<pair<long long,long long>> haha[100001];
vector<long long> edge[100001];
vector<pair<long long,long long>> wut(1,{-LLONG_MAX,0});
vector<long long> pos(100001);
vector<long long> st(100001);
vector<long long> br(100001);
long long bruh[100001][17];
vector<pair<long long,pair<long long,long long>>> idk[100010];
vector<long long> dep(100001);
long long z = 1;
pair<long long,long long> dude(long long x, long long t) {
long long l = 0,r = idk[x].size()-1;
while(l < r) {
long long mid = (l+r+1)/2;
if(idk[x][mid].first > t) {
r = mid-1;
}
else {
l = mid;
}
}
return idk[x][l].second;
}
pair<long long,long long> no(long long r, long long t) {
long long c = 0,a = 0,b = 0;
for(long long i = 17; i >= 0; i--) {
if(c+(1 << i) <= r) {
c+=(1 << i);
pair<long long,long long> d = dude(c,t);
a+=d.first;
b+=d.second;
}
}
return {a,b};
}
void upd(long long a, long long x, long long t) {
long long q = 1;
if(x < 0) {
q = -1;
}
while(a < 100001) {
pair<long long,long long> c = idk[a][idk[a].size()-1].second;
idk[a].push_back({t,{c.first+x,c.second+q}});
a+=((a)&(-a));
}
}
void dfs(long long a, long long t, long long d) {
dep[a] = d;
st[a] = 1;
pos[a] = z;
bruh[a][0] = t;
z++;
for(pair<long long,long long> v: haha[a]) {
if(v.first != t) {
br[v.first]+=br[a];
for(long long x = 0; x < edge[v.second].size(); x++) {
wut.push_back({edge[v.second][x],v.first});
br[v.first]++;
}
dfs(v.first,a,d+1);
st[a]+=st[v.first];
}
}
}
long long lca(long long a, long long b) {
if(dep[a] < dep[b]) {
swap(a,b);
}
long long c = dep[a]-dep[b];
for(long long i = 0; i < 17; i++) {
if((1 << i)&c) {
a = bruh[a][i];
}
}
if(a == b) {
return a;
}
for(long long i = 16; i >= 0; i--) {
if(bruh[a][i] != bruh[b][i]) {
a = bruh[a][i];
b = bruh[b][i];
}
}
return bruh[a][0];
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
long long n,m,q,a,b,x,y;
cin >> n >> m >> q;
for(long long i = 1; i <= n-1; i++) {
cin >> a >> b;
haha[a].push_back({b,i});
haha[b].push_back({a,i});
}
for(long long i = 0; i < m; i++) {
cin >> a >> b;
edge[a].push_back(b);
}
dfs(1,-1,1);
for(long long i = 1; i < 17; i++) {
for(long long j = 1; j <= n; j++) {
if(bruh[j][i-1] == -1) {
bruh[j][i] = -1;
}
else {
bruh[j][i] = bruh[bruh[j][i-1]][i-1];
}
}
}
sort(wut.begin(),wut.end());
for(long long i = 1; i <= 100009; i++) {
idk[i].push_back({0,{0,0}});
}
for(long long i = 1; i < wut.size(); i++) {
long long a = wut[i].second,b = wut[i].first;
a = pos[a];
upd(a,b,i);
upd(a+st[a],-b,i);
}
for(long long i = 0; i < q; i++) {
cin >> a >> b >> x >> y;
long long c = lca(a,b);
long long d = br[a]+br[b]-2*br[c];
a = pos[a];
b = pos[b];
c = pos[c];
long long l = 0,r = wut.size()-1;
while(l < r) {
long long mid = (l+r+1)/2;
if(no(a,mid).first+no(b,mid).first-2*no(c,mid).first <= y) {
l = mid;
}
else {
r = mid-1;
}
}
cout << max(-1LL,x+(no(a,l).second+no(b,l).second-2*no(c,l).second)-d) << "\n";
}
return 0;
}
