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#include <cstdio>
#include <algorithm>
#include <utility>
#include <set>

#define MIN(X, Y) ((X) < (Y) ? (X) : (Y))
#define MAX(X, Y) ((X) > (Y) ? (X) : (Y))

#define MAX_N 200000
#define MAX_K 500000


struct reaction {
	int prio;
	int first;
	int second;
	
	bool operator<(const reaction &other) const {
		return prio < other.prio;
	}
};


int main() {

	int n, m, k, a, b, weight;
	int vials[MAX_N+1];
	std::pair<int, int> steps[MAX_N];
	std::set<reaction> reactions[MAX_N+1];
	std::set<reaction>::iterator it;
	reaction r;
	long long result = 0;


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

	for (int i = 1; i <= n; i++)
		scanf("%d", &vials[i]);

	for (int i = 0; i < m; i++) {
		scanf("%d %d", &a, &b);
		steps[i] = std::make_pair(a, b);
	}

	for (int i = 0; i < k; i++) {
		scanf("%d %d", &a, &b);

		r.prio = i;
		r.first = a;
		r.second = b;
		
		reactions[a].insert(r);
		reactions[b].insert(r);
	}

	for (int i = 0; i < m; i++) {
		a = steps[i].first;
		b = steps[i].second;

		if (reactions[a].size() > reactions[b].size())
			std::swap(reactions[a], reactions[b]);
		// 'a' has less reactions
		for (it = reactions[a].begin(); it != reactions[a].end(); it++) {
			if (reactions[b].insert(*it).second == false) {
				// same reaction in both sets
				weight = MIN(vials[it->first], vials[it->second]);
				result += 2 * weight;
				vials[it->first] -= weight;
				vials[it->second] -= weight;
			}
		}
		reactions[a].clear();
	}

	printf("%lld\n", result);
	return 0;
}