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#include <algorithm>
#include <iostream>
#include <vector>
using namespace std;

const int nmax = 2*1e5+5;
const int tmax = 2*nmax;
const int kmax = 5*1e5+5;
const int logtmax = 20;

typedef long long ll;

int n, m, k;
ll g[nmax];
vector<int> t[tmax];
int tl[tmax];
int tn;

struct {
	int c, d;
	int node;
} mix[kmax];

vector<int> mixorder;

bool mixcmp(const int lhs, const int rhs) {
	if (mix[lhs].node != mix[rhs].node) return mix[lhs].node < mix[rhs].node; //tl[mix[lhs].node] > tl[mix[rhs].node];
	return lhs < rhs;
}

void debugTree() {
	for (int i = 1; i <= tn; i++) {
		cerr << i << ": ";
		for (auto w : t[i]) cerr << w << " ";
		cerr << "\n";
	}
}

struct {
	int T[tmax];
	int P[tmax][logtmax];
	bool vis[tmax];

	void dfs(int v, int f, int level) {
		// cerr << v << " " << f << endl;
		vis[v] = true;
		T[v] = f;
		tl[v] = level;
		for (auto w : t[v]) {
			if (w == f) continue;
			dfs(w, v, level+1);
		}
	}

	int query(int p, int q) {
		int tmp, log, i;

		if (tl[p] < tl[q])
			tmp = p, p = q, q = tmp;

		for (log = 1; (1 << log) <= tl[p]; log++) {} log--;

		for (i = log; i >= 0; i--)
			if (tl[p] - (1 << i) >= tl[q])
				p = P[p][i];

		if (p == q) return p;

		for (i = log; i >= 0; i--)
			if (P[p][i] != -1 && P[p][i] != P[q][i])
				p = P[p][i], q = P[q][i];

		return T[p];
	}

	void build() {
		for (int i = 0; i < tmax; i++) vis[i] = false;
		// cerr << "lca.build()\n";
		// debugTree();
		for (int i = tn; i > 0; i--) {
			if (!vis[i]) {
				t[0].push_back(i); t[i].push_back(0);
				dfs(i, 0, 1);
			}
		}
		// for (int i = 1; i <= tn; i++) {
		// 	cerr << T[i] << " ";
		// } cerr << "\n";

		int i, j;
		for (i = 1; i <= tn; i++) {
			for (j = 0; (1 << j) <= tn; j++)
				P[i][j] = -1;
		}
		for (i = 1; i <= tn; i++) {
			P[i][0] = T[i];
		}
		for (j = 1; (1 << j) <= tn; j++)
			for (i = 1; i <= tn; i++)
				if (P[i][j-1] != -1)
					P[i][j] = P[P[i][j-1]][j-1];
	}
} lca;

void readTree() {
	int f[tmax];
	for (int i = 1; i <= n; i++) f[i] = i;


	tn = n;
	for (int i = 0; i < m; i++) {
		int a, b; cin >> a >> b;

		tn++;
		t[tn].push_back(f[a]); t[tn].push_back(f[b]);
		t[f[b]].push_back(tn); t[f[a]].push_back(tn);
		f[b] = tn; f[a] = tn;
	}
}

int main() {
	ios_base::sync_with_stdio(false);
	cin >> n >> m >> k;
	for (int i = 1; i <= n; i++) cin >> g[i];
	readTree();
	lca.build();

	for (int i = 0; i < k; i++) {
		cin >> mix[i].c >> mix[i].d;
		mix[i].node = lca.query(mix[i].c, mix[i].d);
		// cerr << mix[i].node << " " << mix[i].c << " " << mix[i].d << "\n";
		if (mix[i].node != 0)
			mixorder.push_back(i);
		// else { cerr << '.'; }
	}
	// cerr << '\n';
	// cerr << mixorder.size() << '\n';

	sort(mixorder.begin(), mixorder.end(), mixcmp);

	ll ans = 0;
	for (auto step : mixorder) {
		// cerr << step << ": " << mix[step].c << " " << mix[step].d << " _" << mix[step].node << endl;
		ll diff = min(g[mix[step].c], g[mix[step].d]);
		ans += 2L * diff;
		g[mix[step].c] -= diff; g[mix[step].d] -= diff;
	}

	cout << ans << endl;

	return 0;
}