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#include <cstdio>
#include <iostream>
#include <algorithm>
#include <cstring>
#include <vector>
#include <set>
#include <map>
#include <cmath>
#include <list>
#include <ctime>
#include <sstream>
#include <queue>
#include <stack>
#include <bitset>
// #include <unordered_set>
// #include <unordered_map>
using namespace std;
typedef vector<int> vi;
typedef pair<int,int> pii;
typedef long long ll;
typedef short int sint;
#define FOR(x, b, e) for(int x=(b); x<=(e); ++x)
#define FORD(x, b, e) for(int x=((int)(b))-1; x>=(e); --x)
#define REP(x, n) for(int x=0; x<(n); ++x)
#define VAR(v,n) typeof(n) v=(n)
#define ALL(c) c.begin(),c.end()
#define SIZE(x) ((int)((x).size()))
#define FOREACH(i,c) for(VAR(i,(c).begin());i!=(c).end();++i)
#define PB push_back
#define ST first
#define ND second
#define mp(x,y) make_pair(x,y)
#define DEBUG 1
#define debug(x) {if (DEBUG)cerr <<#x <<" = " <<x <<endl; }
#define debugv(x) {if (DEBUG) {cerr <<#x <<" = "; FOREACH(it, (x)) cerr <<*it <<", "; cout <<endl; }}
#define REMAX(a,b) (a)=max((a),(b));
#define REMIN(a,b) (a)=min((a),(b));
#define wez(n) int (n); scanf("%d",&(n));
#define wez2(n,m) int (n),(m); scanf("%d %d",&(n),&(m));

const int N = 200200;
const int K = 500010;
int g[N];
int p[N];
pii reak[N];
pii kol[K];
int n, m, k;
set<int> elems[N];
ll res;

inline void lacz(const int dest, const int source) {
	for (const int& elem : elems[source]) {
		// przechodze i wybieram
		if (g[kol[elem].ST] > 0 && g[kol[elem].ND] > 0 && elems[dest].find(elem) != elems[dest].end()) {
			int x = kol[elem].ST, y = kol[elem].ND;
			int ile = min(g[x], g[y]);
			g[x] -= ile; g[y] -= ile;
			res = res + 2LL * ile;
		}
	}
	for (const int& elem : elems[source]) {
		if (g[kol[elem].ST] > 0 && g[kol[elem].ND] > 0 && elems[dest].find(elem) == elems[dest].end()) {
			elems[dest].insert(elem);
		}
	}
	elems[source].clear();
}

int find(const int x) {
	if (x != p[x]) p[x] = find(p[x]);
	return p[x];
}

inline void link(const int x, const int y) {
	int a = find(x), b = find(y);
	if (a == b) return ;
	if (SIZE(elems[a]) > SIZE(elems[b])) {
		p[b] = a;
		lacz(a, b);
	} else {
		p[a] = b;
		lacz(b, a);
	}
}

int main() {
	scanf("%d %d %d", &n, &m, &k);
	FOR(i, 1, n) {
		scanf("%d", &g[i]);
		p[i] = i;
	}
	REP(i, m) {
		scanf("%d %d", &reak[i].ST, &reak[i].ND);
	}
	REP(i, k) {
		scanf("%d %d", &kol[i].ST, &kol[i].ND);
		elems[kol[i].ST].insert(i);
		elems[kol[i].ND].insert(i);
	}
	res = 0;
	REP(i, m) {
		link(reak[i].ST, reak[i].ND);
	}
	printf("%lld\n", res);
	return 0;
}