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


int n, m, k;
vector<int> G;
vector<pair<int,int> > S;
vector<pair<int,int> > R;


struct Node{
    int size;
    int parent;
    int preorder;
    int supervisor;
    vector<int> childs;
};
vector<Node> Tree;

void init(){
    Tree.resize(n);
    for(int i=0; i<n; ++i){
        Tree[i].size = 1;
        Tree[i].parent = -1;
        Tree[i].supervisor = i;
    }
}

void merge(int a, int b){
    Node node;
    int node_id = Tree.size();
    int sup_a = Tree[a].supervisor;
    int sup_b = Tree[b].supervisor;

    // Ustawianie wierzcholka
    node.parent = node.supervisor = -1;
    node.size = Tree[sup_a].size + Tree[sup_b].size + 1;
    node.childs.push_back(sup_a); Tree[sup_a].parent = node_id;
    node.childs.push_back(sup_b); Tree[sup_b].parent = node_id;
    Tree[b].supervisor = node_id;
    Tree.push_back(node);
}

void complete_tree(){
    if (m==n-1) return;
    Node node;
    node.parent = node.supervisor = -1;
    node.size = 1;
    for(int i=0; i<Tree.size(); ++i) if (Tree[i].parent==-1){
        node.childs.push_back(i);
        Tree[i].parent = Tree.size();
        node.size += Tree[i].size;
    }
    Tree.push_back(node);
}


int cnt;
void dfs(int v){
    Tree[v].preorder = cnt; ++cnt;
    for(int i=0; i<Tree[v].childs.size(); ++i) dfs(Tree[v].childs[i]);
}
void calculate_preorder(){cnt = 0; dfs(Tree.size()-1);}

bool predecessor(int u, int v){
    if (Tree[u].preorder < Tree[v].preorder) return false;
    return Tree[u].preorder < Tree[v].preorder + Tree[v].size;
}


vector<vector<int> > p;
void calculate_p(){
    p.resize(1, vector<int>(Tree.size()));
    for(int i=0; i<Tree.size(); ++i) if (Tree[i].parent == -1) p[0][i]=i; else p[0][i]=Tree[i].parent;
    bool cont;
    do{
        cont = false;
        vector<int> row(Tree.size());
        for(int i=0; i<Tree.size(); ++i){
            row[i] = p.back()[p.back()[i]];
            if (row[i] != Tree.size()-1) cont = true;
        }
        p.push_back(row);
    } while(cont);
}

int LCA(int u, int v){
    if (predecessor(u, v)) return v;
    if (predecessor(v, u)) return u;
    int i = u;
    int j = p.size()-1;
    while(j>=0){
        if (predecessor(v, p[j][i])) --j;
        else i = p[j][i];
    }
    return p[0][i];
}


int main(){

    // Wczytywanie danych
    scanf("%d %d %d", &n, &m, &k); G.resize(n); S.resize(m); R.resize(k);
    for(int i=0; i<n; ++i) scanf("%d", &G[i]);
    for(int i=0; i<m; ++i) scanf("%d %d", &S[i].first, &S[i].second);
    for(int i=0; i<k; ++i){ scanf("%d %d", &R[i].first, &R[i].second); --R[i].first, --R[i].second; }

    // Tworzenie drzewa i wszystkiego innego
    init();
    for(int i=0; i<m; ++i) merge(S[i].first-1, S[i].second-1);
    complete_tree();
    calculate_preorder();
    calculate_p();

    // Liczenie wyniku
    long long result = 0;
    map<int, vector<pair<int,int> > > M;
    for(int i=0; i<k; ++i) M[LCA(R[i].first, R[i].second)].push_back(R[i]);
    if (m<n-1) M[Tree.size()-1].clear();
    for(map<int, vector<pair<int,int> > >::iterator it=M.begin(); it!=M.end(); ++it){
        vector<pair<int,int> > &V = it->second;
        for(int i=0; i<V.size(); ++i){
            int a = V[i].first;
            int b = V[i].second;
            int x = min(G[a], G[b]);
            result += x; result += x;
            G[a] -= x; G[b] -= x;
        }
    }

    // Wypisywanie wyniku
    printf("%lld\n", result);

}