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#include <cstdio>
#include <vector>
#include <algorithm>
#include <set>
using namespace std;

long long result = 0LL;
std::vector<int> substanceWeights;

struct Triple
{
    Triple(int first_, int second_, int thrid_)
        : first(first_), second(second_), thrid(thrid_)
    {
    }

    int first, second, thrid;
    bool operator <(Triple p) const
    {
        return first < p.first;
    }
};

template <typename SetType>
struct ListJoinSets
{
    ListJoinSets(int n, vector<set<SetType> >& sets) :
        parents_(n), sets_(sets)
    {
        for (int i = 0 ; i < n ; i++)
            parents_[i] = i;
    }
    
    void join(int from, int to)
    {
        //assert(parents_[from] == from);
        parents_[from] = to;
        int smallerSet = sets_[from].size() < sets_[to].size() ? from : to;
        int biggerSet = sets_[from].size() >= sets_[to].size() ? from : to;
        
        for (typename set<SetType>::iterator it = sets_[smallerSet].begin() ; it != sets_[smallerSet].end() ; ++it)
        {
            if (findAncestor(it->second) == to)
            {
                int weight = min(substanceWeights[it->second], substanceWeights[it->thrid]);
                result += 2 * weight;
                substanceWeights[it->second] -= weight;
                substanceWeights[it->thrid] -= weight;
            }
            else
                sets_[biggerSet].insert(*it);
        }
        sets_[to].swap(sets_[biggerSet]);
        sets_[from].clear();
    }

    int findAncestor(int from)
    {
        if (parents_[from] != from)
            parents_[from] = findAncestor(parents_[from]);
        return parents_[from];
    }
    
private:
    vector<int> parents_;
    vector<set<SetType> >   &sets_;
};

int main()
{
    int n, m, k;
    scanf("%d %d %d", &n, &m, &k);
    substanceWeights.resize(n);
    for (int i = 0 ; i < n ; i++)
    {
        int substanceWeight;
        scanf("%d", &substanceWeight);
        substanceWeights[i] = substanceWeight;
    }

    vector<pair<int,int> > joinFromTo;
    joinFromTo.reserve(m);
    for (int i = 0 ; i < m ; i++)
    {
        int from, to;
        scanf("%d %d", &from, &to);
        joinFromTo.push_back(make_pair(--from, --to));
    }
    
    vector<set<Triple> > substitutes(n);
    for (int i = 0 ; i < k ; i++)
    {
        int sub1, sub2;
        scanf("%d %d", &sub1, &sub2);
        --sub1;
        --sub2;
        substitutes[sub1].insert(Triple(i, sub2, sub1));
        substitutes[sub2].insert(Triple(i, sub1, sub2));
    }

    ListJoinSets<Triple> listJoinSets(n, substitutes);     
    for (int i = 0 ; i < m ; i++)
    {
        listJoinSets.join(joinFromTo[i].first, joinFromTo[i].second);
    }
    
    printf("%lld\n", result);

}