#pragma GCC optimize("O3,inline")
#include <bits/stdc++.h>
using namespace std;
int cnt = 0;
vector<vector<int>> adjlist;
vector<int> pre;
void dfs(int n, int p) {
pre[n] = cnt++;
for (int i : adjlist[n]) if (i != p) dfs(i, n);
}
signed main() {
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
int N, M, Q, a, b, c; cin >> N >> M >> Q;
vector<long long> funny(N, 0);
adjlist.resize(N, vector<int>());
pre.resize(N, 0);
vector<pair<int, pair<int, int>>> edges;
for (int i = 0; i < M; i++) {
cin >> a >> b >> c;
adjlist[a].push_back(b);
adjlist[b].push_back(a);
edges.push_back({ c, {a, b} });
}
dfs(0, -1);
for (int i = 0; i < M; i++) funny[max(pre[edges[i].second.first], pre[edges[i].second.second])] = edges[i].first;
for (int i = 1; i < N; i++) funny[i] += funny[i - 1];
for (int i = 0; i < Q; i++) {
cin >> a >> b;
cout << funny.back() - funny[b] + funny[a] << '\n';
}
}
