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#include <cstdio>
#include <cstring>
#include <string>
#include <algorithm>
#include <vector>
#include <stack>
#include <queue>
#include <deque>
#include <list>
#include <set>
#include <map>
#include <cstdlib>
#include <cassert>
#include <cmath>
#include <cstdarg>
using namespace std;
#define ALL(x) (x).begin(), (x).end()
#ifdef DBG
#define DBGprint(format, ...) do { fprintf(stderr, "[%s:%d] " format "\n", __func__, __LINE__, ## __VA_ARGS__); } while (0)
#else
#define DBGprint(...) do { } while (0)
#endif

typedef long double LD;
typedef double DL;
typedef long long LL;
typedef unsigned long long ULL;
typedef pair<LD,LD> PLD;
typedef pair<int,int> PII;
typedef pair<LL,LL> PLL;
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<PII> VPII;
void memcheck()
{
#ifdef DBG
    char c[100];
    FILE *p = fopen("/proc/self/status","r");
    while (fgets(c,100,p) )
        if (strncmp("VmPeak",c,6)==0)
            fputs(c, stderr);
    fclose(p);
#endif
}
//------ /headers --------

int n, m, k;
VI tubes;

LL sediment;
VPII unions;
VPII reactions;

typedef set<int> set_t;
vector<pair<int, set_t>> parent;
int find(int x) {
    if (x != parent[x].first) {
        parent[x].first = find(parent[x].first);
    }
    return parent[x].first;
}
void onion(int x, int y) {
    x = find(x);
    y = find(y);
    if (x == y) {
        return;
    }

//     DBGprint("unitING x %d y %d", x, y);
//     for (int i : parent[x].second) {
//         DBGprint("set[x]: %d (%d-%d  with %d, %d)", i,
//                 reactions[i].first, reactions[i].second, tubes[reactions[i].first], tubes[reactions[i].second]);
//     }
//     for (int i : parent[y].second) {
//         DBGprint("set[y]: %d (%d-%d  with %d, %d)", i,
//                 reactions[i].first, reactions[i].second, tubes[reactions[i].first], tubes[reactions[i].second]);
//     }

    if (parent[x].second.size() > parent[y].second.size()) {
        swap(x, y);
    }

    for (int w : parent[x].second) {
        // musimy przelatywac od najmniejszych
        auto it = parent[y].second.find(w);
        if (it == parent[y].second.end()) {
            parent[y].second.insert(w);
        } else {
            // osad!
            int s = min(tubes[reactions[w].first], tubes[reactions[w].second]);
            DBGprint("while uniting %d %d found %d (sedim %d)", x, y, w, s);
            tubes[reactions[w].first] -= s;
            tubes[reactions[w].second] -= s;
            sediment += 2 * s;
        }
    }

    parent[x].first = y;
    parent[x].second.clear();

//     DBGprint("united x %d y %d", x, y);
//     for (int i : parent[x].second) {
//         DBGprint("set[x]: %d (%d-%d  with %d, %d)", i,
//                  reactions[i].first, reactions[i].second, tubes[reactions[i].first], tubes[reactions[i].second]);
//     }
//     for (int i : parent[y].second) {
//         DBGprint("set[y]: %d (%d-%d  with %d, %d)", i,
//                  reactions[i].first, reactions[i].second, tubes[reactions[i].first], tubes[reactions[i].second]);
//     }
}


int main() {
    scanf("%d%d%d", &n, &m, &k);

    for (int i = 0; i < n; ++i) {
        int tmp;
        scanf("%d", &tmp);
        tubes.push_back(tmp);
        parent.emplace_back(i, set_t());
    }

    for (int i = 0; i < m; ++i) {
        int a, b;
        scanf("%d%d", &a, &b);
        unions.emplace_back(a - 1, b - 1);
    }

    for (int i = 0; i < k; ++i) {
        int a, b;
        scanf("%d%d", &a, &b);
        --a;
        --b;
        parent[a].second.insert(i);
        parent[b].second.insert(i);
        reactions.emplace_back(a, b);
    }

    for (const PII& uni : unions) {
        onion(uni.first, uni.second);
    }

    printf("%lld\n", sediment);

    memcheck();
}