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

using namespace std;

typedef unordered_map<int,int> UMII;
struct R {
	int o, a, b;
	R() : o(-1), a(0), b(0) {}
	R(int o, int a, int b) : o(o), a(a), b(b) {}
};
struct R_comp {
	bool operator() (const R &r1, const R &r2) const { return r1.o < r2.o; }
};
typedef set<R,R_comp> SR;
typedef vector<R> VR;
struct P {
	UMII g;
	SR r;
};
typedef vector<P> VP;
typedef pair<int,int> PII;
typedef vector<PII> VPII;
typedef long long ll;

int n, m, k, a, b;
VP p;
VPII s;
VR ar;
ll o;

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

	p.resize(n + 1);
	for (int i = 1; i <= n; ++i) {
		scanf("%d", &a);
		p[i].g[i] = a;
	}

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

	ar.resize(k);
	for (int i = 1; i <= k; ++i) {
		scanf("%d %d", &a, &b);
		p[a].r.insert(R(i, a, b));
		p[b].r.insert(R(i, a, b));
	}

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

		p[b].g.insert(p[a].g.begin(), p[a].g.end());
		p[a].g.clear();

		VR::iterator ar_end = set_intersection(
			p[a].r.begin(), p[a].r.end(),
			p[b].r.begin(), p[b].r.end(),
			ar.begin(), R_comp());

		for (VR::iterator it = ar.begin(); it != ar_end; ++it) {
			if (p[b].g[it->a] < p[b].g[it->b]) {
				o += 2LL * p[b].g[it->a];
				p[b].g[it->b] -= p[b].g[it->a];
				p[b].g[it->a] = 0;
			} else {
				o += 2LL * p[b].g[it->b];
				p[b].g[it->a] -= p[b].g[it->b];
				p[b].g[it->b] = 0;
			}
			if (p[b].g[it->a] == 0)
				p[b].g.erase(it->a);
			if (p[b].g[it->b] == 0)
				p[b].g.erase(it->b);
		}
		
		p[b].r.insert(p[a].r.begin(), p[a].r.end());
		p[a].r.clear();

		for (SR::iterator it = p[b].r.begin(); it != p[b].r.end(); )
			if (p[b].g.find(it->a) == p[b].g.end() && p[b].g.find(it->b) == p[b].g.end())
				p[b].r.erase(it++);
			else
				++it;
	}

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