#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
#define ff first
#define ss second
#define all(x) begin(x), end(x)
#define FOR(i, a, b) for(int i = (a); i < (b); i++)
#define F0R(i, x) FOR(i, 0, x)
#define FORd(i, a, b) for(int i = (b)-1; i >= (a); i--)
#define F0Rd(i, x) FORd(i, 0, x)
const int MAX_N = 10;
const ll INF = 1e18;
int n, m, q, t, cnt;
int idx[MAX_N], lst[MAX_N], sz[MAX_N], dep[MAX_N], anc[MAX_N][20], rt[MAX_N], ch[40*MAX_N][2];
ll sm[40*MAX_N], num[40*MAX_N];
vector<ll> nums[MAX_N];
vector<pii> adj[MAX_N];
int upd(int x, ll l, ll r, ll v){
ll x2 = ++cnt, m = (l+r)/2ll;
if(l == r){
sm[x2] += v;
num[x2]++;
return x2;
}
if(v <= m){
ch[x2][0] = upd(ch[x][0], l, m, v);
ch[x2][1] = ch[x][1];
} else{
ch[x2][0] = ch[x][0];
ch[x2][1] = upd(ch[x][1], m+1ll, r, v);
}
sm[x2] = sm[ch[x2][0]]+sm[ch[x2][1]];
num[x2] = num[ch[x2][0]]+num[ch[x2][1]];
return x2;
}
ll qry1(int x, ll l, ll r, ll ql, ll qr){
if(!x || ql > r || qr < l) return 0;
if(ql <= l && qr >= r) return sm[x];
ll m = (l+r)/2ll;
return qry1(ch[x][0], l, m, ql, qr)+qry1(ch[x][1], m+1, r, ql, qr);
}
ll qry2(int x, ll l, ll r, ll ql, ll qr){
if(!x || ql > r || qr < l) return 0;
if(ql <= l && qr >= r) return num[x];
ll m = (l+r)/2ll;
return qry2(ch[x][0], l, m, ql, qr)+qry2(ch[x][1], m+1, r, ql, qr);
}
int dfs1(int curr, int par){
sz[curr] = 1;
vector<pii> nadj;
for(auto x : adj[curr]){
if(x.ff == par) continue;
nadj.push_back(x);
dep[x.ff] = dep[curr]+1;
anc[x.ff][0] = curr;
sz[curr] += dfs1(x.ff, curr);
}
adj[curr] = nadj;
for(auto &x : adj[curr])
if(sz[x.ff] > sz[adj[curr][0].ff])
swap(x, adj[curr][0]);
return sz[curr];
}
void dfs2(int curr){
idx[curr] = t++;
for(auto x : adj[curr]){
if(x == adj[curr][0]) lst[x.ff] = lst[curr];
else lst[x.ff] = x.ff;
rt[t] = rt[t-1];
for(auto y : nums[x.ss])
rt[t] = upd(rt[t], 0, 1e9, y);
dfs2(x.ff);
}
}
int lca(int a, int b){
if(dep[a] > dep[b]) swap(a, b);
F0Rd(i, 20) if(dep[a]+(1 << i) <= dep[b])
b = anc[b][i];
if(a == b) return a;
F0Rd(i, 20) if(anc[a][i] != anc[b][i])
a = anc[a][i], b = anc[b][i];
return anc[a][0];
}
pll solve(int a, int b, ll x){ // number of things > x, sum of things <= x
pll ans = {0, 0};
int c = lca(a, b);
F0R(i, 2){
while(a != c){
int y = lst[a]; if(dep[y] < c) y = c;
ans.ff += qry2(rt[idx[a]], 0, 1e9, x+1ll, 1e9)-qry2(rt[idx[y]-(y != c)], 0, 1e9, x+1ll, 1e9);
ans.ss += qry1(rt[idx[a]], 0, 1e9, 0, x)-qry1(rt[idx[y]-(y != c)], 0, 1e9, 0, x);
if(y != c) a = anc[y][0];
else a = y;
}
swap(a, b);
}
return ans;
}
int main(int argc, const char * argv[]){
cin.tie(0)->sync_with_stdio(0);
cin.exceptions(cin.failbit);
cin >> n >> m >> q;
F0R(i, n-1){
int a, b; cin >> a >> b; a--, b--;
adj[a].push_back({b, i});
adj[b].push_back({a, i});
}
F0R(i, m){
int a, b; cin >> a >> b; a--;
nums[a].push_back(b);
}
dfs1(0, -1);
FOR(x, 1, 20) F0R(i, n)
anc[i][x] = anc[anc[i][x-1]][x-1];
dfs2(0);
F0R(i, q){
ll s, t, x, y; cin >> s >> t >> x >> y; s--, t--;
ll l = 0, r = min(y+1ll, (ll) 1e9);
while(l+1 < r){
ll mid = (l+r)/2ll;
if(solve(s, t, mid).ss <= y) l = mid;
else r = mid;
}
pll z = solve(s, t, l);
if(z.ff > x) cout << -1 << '\n';
else cout << x-z.ff << '\n';
}
return 0;
}
