// The 22nd Japanese Olympiad in Informatics (JOI 2022/2023)
// Spring Training/Qualifying Trial
// March 18–22, 2023 (Komaba, Tokyo)
#include <bits/stdc++.h>
#define ll long long
#define int long long
#define ld long double
#define el cout << '\n'
#define f1(i,n) for(int i=1;i<=n;i++)
#define __file_name ""
using namespace std;
const ll maxn = 4e5+5, inf=1e18;
struct FenwickTree{
int n;
vector<long long> bit;
FenwickTree(){}
FenwickTree(int n): n(n), bit(n+1, 0LL){}
void update(int idx, long long v){
if(idx <= 0) return;
for(;idx<=n;idx+=(idx&-idx)) bit[idx]+=v;
}
long long getSum(int idx){
if(idx <= 0) return 0;
long long res = 0;
for(;idx;idx-=idx&-idx) res += bit[idx];
return res;
}
};
struct Query{
int s, t, x, y, lc, l, r, mid, idx;
bool operator<(const Query &rhs) const{
return mid < rhs.mid;
}
};
struct Edge{
int u, v, w;
Edge(){};
Edge(int u, int v, int w): u(u), v(v), w(w){};
bool operator<(const Edge &rhs) const{
return w > rhs.w;
}
bool operator>(const Edge &rhs) const{
return w < rhs.w;
}
};
int n,m,q,depth[maxn],ans[maxn];
int up[18][maxn];
vector<int> G[maxn];
Edge edges[maxn],ee[maxn];
FenwickTree fen,bit;
Query qu[maxn];
void binlift(int u, int p){
up[0][u] = p;
for(int i=1;i<18;i++){
up[i][u] = up[i-1][up[i-1][u]];
}
for(int c: G[u]){
if(c != p){
depth[c] = depth[u] + 1;
binlift(c, u);
}
}
}
void jump(int& u, int len){
for(int i=0;i<18;i++){
if(len & (1 << i)) u = up[i][u];
}
}
int LCA(int u, int v){
if(depth[u] > depth[v]) swap(u, v);
jump(v, depth[v] - depth[u]);
if(u == v) return u;
for(int i=17;i>=0;i--){
if(up[i][u] != up[i][v]){
u = up[i][u];
v = up[i][v];
}
}
return up[0][u];
}
int sp[maxn],ep[maxn],timer;
void tour(int u, int p){
sp[u] = timer++;
for(int c: G[u]){
if(c != p) tour(c, u);
}
ep[u] = timer;
}
ll V(int u){
return fen.getSum(sp[u]);
}
ll V2(int u){
return bit.getSum(sp[u]);
}
void check(int i, int &ptr){
while(qu[ptr].mid == i){
if(qu[ptr].l > qu[ptr].r){
ptr++;
continue;
}
ll sum = 1LL * V(qu[ptr].s) + V(qu[ptr].t) - 2*V(qu[ptr].lc);
// cout << i << ' ' << qu[ptr].s << ' ' << qu[ptr].t << ' ' << sum;el;
if(sum <= qu[ptr].y) qu[ptr].l = qu[ptr].mid + 1;
else qu[ptr].r = qu[ptr].mid - 1;
qu[ptr].mid = (qu[ptr].l + qu[ptr].r) / 2;
ptr++;
}
}
bool cmp(Query x, Query y){
return x.r < y.r;
}
signed main(){
ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
if(fopen(__file_name ".inp", "r")){
freopen(__file_name ".inp","r",stdin);
freopen(__file_name ".out","w",stdout);
}
// code here
cin >> n >> m >> q;
fen = FenwickTree(n);
f1(i,n-1){
int u, v; cin >> u >> v;
ee[i] = Edge(u, v, 0);
G[u].push_back(v);
G[v].push_back(u);
}
depth[1] = 1;
binlift(1, 0);
timer = 1;
tour(1, 0);
int ttt = 0;
f1(i,m){
int p, c; cin >> p >> c;
edges[i] = ee[p];
edges[i].w = c;
if(depth[edges[i].u] < depth[edges[i].v]) swap(edges[i].u, edges[i].v);
// cout << edges[i].u << ' ' << edges[i].v << ' ' << depth[edges[i].u] << " ?? " << depth[edges[i].v];el;
}
// sort(edges+1,edges+n);
sort(edges+1,edges+m+1,greater<Edge>());
// f1(i,m){
// cout << edges[i].u << " -> " << edges[i].v << " w = " << edges[i].w;el;
// }
f1(i,q){
cin >> qu[i].s >> qu[i].t >> qu[i].x >> qu[i].y;
qu[i].idx = i;
qu[i].lc = LCA(qu[i].s, qu[i].t);
qu[i].l = 0; qu[i].r = m;
}
qu[q+1].mid = 2e9;
f1(_,30){
f1(i,q) qu[i].mid = (qu[i].l + qu[i].r) / 2;
sort(qu+1,qu+q+1);
fen = FenwickTree(n + 1);
int ptr = 1;
ll sum = 0;
// v is the parent of u
f1(i,m){
check(i-1, ptr);
fen.update(sp[edges[i].u], edges[i].w);
fen.update(ep[edges[i].u], -edges[i].w);
// cout << edges[i].u << " -> " << edges[i].v;el;
}
check(m, ptr);
}
bit = FenwickTree(n+1);
sort(qu+1,qu+q+1,cmp);
int ptr = q;
for(int i=m;i>=1;i--){
while(qu[ptr].r == i){
ll sum = V2(qu[ptr].s) + V2(qu[ptr].t) - 2*V2(qu[ptr].lc);
// cout << qu[ptr].idx << ' ' << qu[ptr].r <<
ans[qu[ptr].idx] = qu[ptr].x - sum;
ptr--;
}
bit.update(sp[edges[i].u], 1);
bit.update(ep[edges[i].u], -1);
}
qu[0].r = -1;
while(qu[ptr].r == 0){
ll sum = V2(qu[ptr].s) + V2(qu[ptr].t) - 2*V2(qu[ptr].lc);
// cout << qu[ptr].idx << ' ' << qu[ptr].r <<
ans[qu[ptr].idx] = qu[ptr].x - sum;
ptr--;
}
f1(i,q) cout << (ans[i] >= 0 ? ans[i] : -1) << '\n';
return 0;
}
