This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
#define Y8o "TwoCurrencies"
#define maxn (int) 1e5 + 5
#define ll long long
#define pii pair<int, int>
#define gb(i, j) ((i >> j) & 1)
#define all(x) x.begin(), x.end()
#define _left id * 2, l, mid
#define _right id * 2 + 1, mid + 1, r
#define fi(i, a, b) for(int i = a; i <= b; i ++)
#define fid(i, a, b) for(int i = a; i >= b; i --)
#define f first
#define s second
using namespace std;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
ll GetRandom(ll l, ll r) {
    return uniform_int_distribution<ll> (l, r) (rng);
}
void iof() {
    ios_base::sync_with_stdio(0);
    cin.tie(NULL), cout.tie(NULL);
    if(fopen(Y8o".inp", "r"))
    {
        freopen(Y8o".inp", "r", stdin);
//        freopen(Y8o".out", "w", stdout);
    }
}
void ctime() {
    cerr << "\n" << "\nTime elapsed: " << 1000 * clock() / CLOCKS_PER_SEC << "ms\n";
}
int n, m, Q, N;
pii ed[maxn];
vector<int> o[maxn];
int in[maxn], out[maxn], cnt;
int h[maxn], cha[maxn][17];
vector<pii> cur;
struct dl { int u, v; ll g, si; } qr[maxn];
int L[maxn], R[maxn], ans[maxn];
vector<int> st[maxn];
struct BIT {
    ll bit[maxn];
    void build() {
        fi(i, 1, n) bit[i] = 0;
    }
    void update(int x, ll val) {
        while(x <= n) bit[x] += val, x += (x & -x);
    }
    ll get(int x, ll sum = 0) {
        while(x > 0) sum += bit[x], x -= (x & -x);
        return sum;
    }
    void upR(int l, int r, ll val) {
        update(l, +val), update(r + 1, -val);
    }
} Bit;
void dfs(int u = 1, int p = 0) {
    in[u] = ++cnt;
    for(int v : o[u]) if(v != p) {
        h[v] = h[u] + 1, cha[v][0] = u;
        fi(i, 1, 16) cha[v][i] = cha[cha[v][i - 1]][i - 1];
        dfs(v, u);
    }
    out[u] = cnt;
}
int lca(int u, int v) {
    if(h[u] < h[v]) swap(u, v);
    int kc = h[u] - h[v];
    fid(i, 16, 0) if(gb(kc, i)) u = cha[u][i];
    fid(i, 16, 0) if(cha[u][i] != cha[v][i]) u = cha[u][i], v = cha[v][i];
    return u == v ? u : cha[u][0];
}
ll weight(int u, int v) {
    return Bit.get(in[u]) + Bit.get(in[v]) - 2ll*Bit.get(in[lca(u, v)]);
}
void solve() {
    cin >> n >> m >> Q;
    fi(i, 1, n - 1) {
        int u, v; cin >> u >> v;
        o[u].push_back(v), o[v].push_back(u);
        ed[i] = { u, v };
    }
    dfs();
    fi(i, 1, n - 1) {
        int &u = ed[i].f, &v = ed[i].s;
        if(cha[u][0] == v) swap(u, v);
    }
    fi(i, 1, m) {
        int id, val; cin >> id >> val;
        cur.push_back({ val, id });
    }
    sort( all(cur) );
    N = cur.size() - 1;
    fi(i, 1, Q) {
        int u, v; ll g, si; cin >> u >> v >> g >> si;
        qr[i] = { u, v, g, si };
        L[i] = 0, R[i] = N;
        ans[i] = g;
    }
    while(1) {
        int ok = 1;
        fi(i, 1, Q) if(L[i] <= R[i]) {
            ok = 0;
            st[ (L[i] + R[i]) >> 1 ].push_back(i);
        }
        if(ok) break;
        Bit.build();
        fi(_, 0, N) {
            int val, i; tie(val, i) = cur[_];
            int u, v; tie(u, v) = ed[i];
            Bit.upR(in[v], out[v], +val);
            while(st[_].size()) {
                int id = st[_].back(); st[_].pop_back();
                int u = qr[id].u, v = qr[id].v;
                ll g = qr[id].g, si = qr[id].si;
                if(si >= weight(u, v)) L[id] = _ + 1;
                else R[id] = _ - 1;
            }
        }
    }
    fi(i, 1, Q) st[R[i] + 1].push_back(i);
    Bit.build();
    fid(_, N, 0) {
        int val, i; tie(val, i) = cur[_];
        int u, v; tie(u, v) = ed[i];
        Bit.upR(in[v], out[v], +1);
        while(st[_].size()) {
            int id = st[_].back(); st[_].pop_back();
            int u = qr[id].u, v = qr[id].v;
            ll g = qr[id].g, si = qr[id].si;
            ans[id] -= weight(u, v);
        }
    }
    fi(i, 1, Q) cout << max(ans[i], -1) << '\n';
}
int main() {
    iof();
    int nTest = 1;
//    cin >> nTest;
    while(nTest --) {
        solve();
    }
    ctime();
    return 0;
}
Compilation message (stderr)
currencies.cpp: In function 'void solve()':
currencies.cpp:128:20: warning: unused variable 'g' [-Wunused-variable]
  128 |                 ll g = qr[id].g, si = qr[id].si;
      |                    ^
currencies.cpp:146:16: warning: unused variable 'g' [-Wunused-variable]
  146 |             ll g = qr[id].g, si = qr[id].si;
      |                ^
currencies.cpp:146:30: warning: unused variable 'si' [-Wunused-variable]
  146 |             ll g = qr[id].g, si = qr[id].si;
      |                              ^~
currencies.cpp: In function 'void iof()':
currencies.cpp:27:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   27 |         freopen(Y8o".inp", "r", stdin);
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