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#include <cstdio>
#include <cstdlib>
#include <ctime>
#include <vector>
#include <string>
#include <queue>
#include <map>
#include <set>
#include <algorithm>
using namespace std;

//#define MJMREAD

typedef long long ll;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<int,int> pii;




#if defined(MJMREAD)
int rd[] = {12,11,66, 0,0,0,0,0,0,0,0,0,0,0,0, 1,2,3,4,5,6,7,8,9,10,11,12,2,4,6,8,10,12,4,8,8,12, 1,2,1,3,1,4,1,5,1,6,1,7,1,8,1,9,1,10,1,11,1,12,2,3,2,4,2,5,2,6,2,7,2,8,2,9,2,10,2,11,2,12,3,4,3,5,3,6,3,7,3,8,3,9,3,10,3,11,3,12,4,5,4,6,4,7,4,8,4,9,4,10,4,11,4,12,5,6,5,7,5,8,5,9,5,10,5,11,5,12,6,7,6,8,6,9,6,10,6,11,6,12,7,8,7,9,7,10,7,11,7,12,8,9,8,10,8,11,8,12,9,10,9,11,9,12,10,11,10,12,11,12};
inline int read() { static int i=0; return rd[i++]; }
#else // MJMREAD
inline int read() { int n; scanf("%d", &n); return n; }
#endif // MJMREAD


class FU {
    std::vector<int> p;
public:
    FU(int n);
    int f(int x);                   // find
    void u(int x, int y);           // union
    bool s(int x, int y);           // are x and y in the same set?
    int a();                        // add new element as singleton, return id of new element
    int size(int x);                // return number of elements in set containing x
    int operator()(int x);          // alias for f
    bool operator()(int x, int y);  // alias for s
};

FU::FU(int n) : p(n, -1) {}

int FU::f(int x) {
    int t, r = x;
    while (p[r] >= 0)
        r = p[r];
    while (x != r)
        t = p[x],
        p[x] = r,
        x = t;
    return r;
}

void FU::u(int x, int y) {
    x = f(x);
    y = f(y);
    if (x == y)
        return;
    if (p[x] < p[y])
        p[x] += p[y], p[y] = x;
    else
        p[y] += p[x], p[x] = y;
}

bool FU::s(int x, int y) { return f(x) == f(y); }

int FU::a() { p.push_back(-1); return p.size() - 1; }

int FU::size(int x) { return -p[f(x)]; }

int FU::operator()(int x) { return f(x); }

bool FU::operator()(int x, int y) { return s(x, y); }



// http://pl.wikipedia.org/wiki/Algorytm_Tarjana

void tarjanOLCA(int u, FU &fu, vi &ancestor, vector<bool> &color, vi &child1, vi &child2, vector<pii> &synthesis, vvi &tmp, vvi &final, int &n, int &m) {
    ancestor[u] = u;
    if (u >= n) {
        tarjanOLCA(child1[u-n], fu, ancestor, color, child1, child2, synthesis, tmp, final, n, m);
        fu.u(u, child1[u-n]);
        ancestor[fu.f(u)] = u;
        tarjanOLCA(child2[u-n], fu, ancestor, color, child1, child2, synthesis, tmp, final, n, m);
        fu.u(u, child2[u-n]);
        ancestor[fu.f(u)] = u;
    }
    color[u] = true;
    if (u < n) for (int i=0; i<tmp[u].size(); ++i) {
        int id = tmp[u][i];
        int v = synthesis[id].first + synthesis[id].second - u;
        if (color[v])
            final[ancestor[fu.f(v)] - n].push_back(id);
    }
}

int main() {
    int n = read();
    int m = read();
    int k = read();

    vi weight(n);
    FU phialId(n);
    vi realPhial(n);
    vi parent(n+m, -1);
    vi child1(m), child2(m);
    vi ancestor(n+m);
    vector<bool> color(n+m, false);
    vector<pii> synthesis(k);
    vvi tmp(n);
    vvi final(m);
    set<int> roots;
    FU fu(n+m);

    for (int i=0; i<n; ++i) {
        weight[i] = read();
        realPhial[i] = i;
    }

    for (int i=0; i<m; ++i) {
        int a = read() - 1;
        int b = read() - 1;
        int aa = phialId.f(a);
        int bb = phialId.f(b);
        int aaa = realPhial[aa];
        int bbb = realPhial[bb];
        phialId.u(aa, bb);
        realPhial[phialId.f(aa)] = parent[aaa] = parent[bbb] = n+i;
        roots.erase(aaa);
        roots.erase(bbb);
        roots.insert(n+i);
        child1[i] = aaa;
        child2[i] = bbb;
    }

    for (int i=0; i<k; ++i) {
        int a = read() - 1;
        int b = read() - 1;
        synthesis[i].first = a;
        synthesis[i].second = b;
        tmp[a].push_back(i);
        tmp[b].push_back(i);
    }
    
    for (set<int>::iterator it = roots.begin(); it != roots.end(); ++it) {
        tarjanOLCA(*it, fu, ancestor, color, child1, child2, synthesis, tmp, final, n, m);
    }

    ll res = 0;
    for (int i=0; i<m; ++i) {
        for (int j=0; j<final[i].size(); ++j) {
            int id = final[i][j];
            int cur = std::min(weight[synthesis[id].first], weight[synthesis[id].second]);
            res += 2*cur;
            weight[synthesis[id].first] -= cur;
            weight[synthesis[id].second] -= cur;
            //fprintf(stderr, "%d: %d %d\n", 1+i, 1+synthesis[id].first, 1+synthesis[id].second);
        }
    }
    printf("%lld\n", res);

    return 0;
}