#include <iostream>
#include <fstream>
#include <vector>
#include <algorithm>

using namespace std;

//http://www.infoarena.ro/problema/radiatie
ofstream fout("radiatie.out") ;

struct muchie
{
    int x ;
    int y;
    int c ;
};

struct sol
{
    int x ;
    int y ;
};

int maxm = 0 ;
bool vizitat[15000] ;
sol S[15000] ;
int g[15000] , r[15000] ;

vector<muchie> M ;
vector<muchie> MUC ;

int n , m , k ;

void citire()
{
    ifstream fin("radiatie.in") ;
    muchie m1 ;
    int i ;
    fin >> n >> m >> k ;
    for ( i = 1 ; i <= m ; i++ )
    {
        fin >> m1.x ;
        fin >> m1.y ;
        fin >> m1.c ;
        M.push_back(m1) ;
    }
    for ( i = 1 ; i <= k ; i++ )
        fin >> S[i].x >> S[i].y ;
}

void DFS(int nodi , int nodf)
{
    //cout << " intrare in dfs " << nodi << " " << nodf << endl ;
    vizitat[nodi] = true ;
    for ( int idx = 0 ; idx < MUC.size() ; idx++ )
    {
        if ( nodi == nodf )
        {
            //cout << " am terminat ciclul " << maxm << endl ;
            fout << maxm << '\n' ;
            return;
        }
        if ( !vizitat[MUC[idx].y] && MUC[idx].x == nodi )
        {
            if ( maxm < MUC[idx].c )
            {
                maxm = MUC[idx].c ;
                //cout << " schimb pt muchia " << MUC[idx].x << " " << MUC[idx].y << " cu val " << MUC[idx].c << endl ;
            }
            DFS(MUC[idx].y,nodf) ;
        }
    }
}

bool compara(muchie m1 , muchie m2)
{
    return m1.c < m2.c ;
}

int root ( int x )
{
    while ( x != g[x] )
        x = g[x] ;
    return x ;
}

void unite ( int x , int y )
{
    if ( r[x] < r[y] )
        g[y] = x;
    if ( r[x] > r[y] )
        g[x] = y ;
    if ( r[x] == r[y] )
    {
        g[y] = x ;
        r[x]++ ;
    }
}

void solve()
{
    int r1 , r2 ;
    int i ;
    for ( i = 1 ; i <= n ; i++ )
        g[i] = i ;
    for ( i = 1 ; i <= m ; i++ )
    {
        //cout << " tabloul g " ;
        r1 = root(M[i-1].x) ;
        r2 = root(M[i-1].y) ;
        //cout << " r1 " << r1 << " r2 " << r2 << endl ;
        if ( r1 != r2 )
        {
            unite(r1,r2) ;
            MUC.push_back(M[i-1]) ;
            //cout << " am adaugat muchia " << M[i-1].x << " " << M[i-1].y << " cu costul " << M[i-1].c << endl ;
        }
    }
}

int main()
{
    citire() ;
    int j , cocos , i ;
    sort(M.begin(),M.end(),compara) ;
    solve() ;
  /*  for ( j = 0 ; j < MUC.size() ; j++ )

cout << " am muchie " << MUC[j].x << " la " << MUC[j].y << " cu val " << MUC[j].c << endl ;*/
    //cout << " k este " << k << endl ;
    for ( i = 1 ; i <= k ; i++ )
    {
        //cout << " k este " << k << endl ;
        maxm = 0 ;
        for ( j = 1 ; j <= n ; j++ )
            vizitat[j] = false ;
        //cout << " urmeaza apel recursiv pt " << S[i].x << " " << S[i].y << endl ;
        if ( S[i].x > S[i].y )
            DFS(S[i].y , S[i].x) ;
        else
            DFS(S[i].x , S[i].y ) ;

    }
}