#include <fstream>
#include <cstring>
#include <vector>
#include <queue>
#define dim 100005
using namespace std;
int n, m, query, i, j, d[dim], a, b, c, nr, cost;
int nod;
queue <int> q[dim];
int viz[dim];
vector < pair <int, int> > g[dim];
ifstream fin ("tollroads.in");
ofstream fout ("tollroads.out");

int bfs (int nod)
{
    int nr=0;
    q[0].push(nod);
    for (i=0;i<=cost;i++) {
        while (!q[i].empty()) {
            int x=q[i].front();
            q[i].pop();
            for (j=0;j<g[x].size();j++) {
                int v=g[x][j].first;
                int c=g[x][j].second;
                if (d[x]+c<=cost && d[v]>d[x]+c) {
                    q[d[x]+c].push(v);
                    d[v]=d[x]+c;
                }
            }
            if(viz[x]==0)
                 nr++;
            viz[x]=1;

        }
    }
    return nr;
}

int main () {
    fin>>n>>m>>query;
    for (i=1;i<=m;i++) {
        fin>>a>>b>>c;
        g[a].push_back({b,c});
        g[b].push_back({a,c});
    }
    for (i=1;i<=query;i++) {
        fin>>nod>>cost;
        fout<<bfs(nod)<<"\n";
        memset (viz, 0, sizeof(viz));
        memset (d, 0, sizeof(d));
    }

    return 0;
}