#include <bits/stdc++.h>
#define int long long
using namespace std;
typedef pair<int,int> pii;
int n;
/*vector<int> par, rnk;
void init(int n) {
par.resize(n); for(int i=0;i<n;i++) par[i]=i;
rnk.resize(n); for(int i=0;i<n;i++) rnk[i]=1;
}
int root(int n) {
if(par[n]==n) return n;
else par[n] = root(par[n]);
return par[n];
}
void merge(int a, int b) {
int pa = root(a), pb = root(b);
if(rnk[pa] >= rnk[pb]) {
par[pb]=pa;
if(rnk[pa]==rnk[pb]) rnk[pa]++;
}
else {
par[pa]=pb;
}
}
bool sameSet(int a, int b) {
return root(a) == root(b);
}
int find_mst(vector<pair<int,pii>> edges, vector<int> src) {
init(n);
for(int i=0;i<src.size()-1;i++) {
merge(src[i],src[i+1]);
}
//sort(edges.begin(),edges.end());
vector<pii> mst;
int cost=0;
for(pair<int,pii> x: edges) {
int w = x.first, a = x.second.first, b = x.second.second;
if(!sameSet(a,b)) {
mst.push_back({a,b});
cost+=w;
merge(a,b);
}
}
return cost;
}*/
signed main() {
int m,q; cin>>n>>m>>q;
//vector<pair<int,pii>> edges(m);
int edges[n-1];
for(int i=0;i<m;i++) {
int a,b,w; cin>>a>>b>>w;
//edges[i] = {w,{a,b}};
if(a>b)swap(a,b);
edges[a]=w;
}
int psum[n]; psum[0]=0; int cur=0;
for(int i=0;i<n-1;i++) {
cur+=edges[i];
psum[i+1]=cur;
}
//sort(edges.begin(),edges.end());
for(int i=0;i<q;i++) {
int l,r; cin>>l>>r;
/*vector<int> src;
for(int j=l;j<=r;j++) {
src.push_back(j);
}
cout<<find_mst(edges, src)<<"\n";*/
cout<<psum[l]+psum[n-1]-psum[r]<<"\n";
}
return 0;
}
