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#include <iostream>
#include <cstdio>
#include <algorithm>
#include <vector>
#include <list>
#include <queue>
#include <stack>
#include <map>
#include <set>
#include <cmath>
#include <string>
#include <cstring>
using namespace std;

typedef long long int LL;
typedef long double LD;
typedef vector<int> VI;
typedef vector<LL> VLL;
typedef vector<LD> VLD;
typedef vector<string> VS;
typedef pair<int, int> PII;
typedef vector<PII> VPII;

const int INF = 1000000001;
const LD EPS = 10e-9;

#define FOR(x, b, e) for(int x = b; x <= (e); ++x)
#define FORD(x, b, e) for(int x = b; 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 FORE(i, c) for(VAR(i, (c).begin()); i != (c).end(); ++i)
#define MP make_pair
#define PB push_back
#define ST first
#define ND second
#define abs(a) ((a)<0 ? -(a) : (a))
#define max(a, b) ((a) > (b) ? (a) : (b))
#define min(a, b) ((a) < (b) ? (a) : (b))

const int MAX_N = 200005;
const int MAX_K = 500005;

struct para
{
	int a, b;
}seq[MAX_N], react[MAX_K];

int n, m, k;
int g[MAX_N];
set<int>* reqp[MAX_N];
set<int> req[MAX_N]; 
LL res;

int main()
{
	scanf("%d %d %d", &n, &m, &k);
	FOR(i, 1, n) 
	{
		scanf("%d", &g[i]);
		reqp[i] = &req[i];
	}
	REP(i, m)
	{
		scanf("%d %d", &seq[i].a, &seq[i].b);
	}
	REP(i, k)
	{
		scanf("%d %d", &react[i].a, &react[i].b);
		reqp[react[i].a]->insert(i);
		reqp[react[i].b]->insert(i);	
	}
	
	REP(i, m)
	{
		if(reqp[seq[i].a]->size() < reqp[seq[i].b]->size())
		{
			for(int r : *reqp[seq[i].a])
			{
				if(reqp[seq[i].b]->find(r) != reqp[seq[i].b]->end())
				{
					int osad = min(g[react[r].a], g[react[r].b]);
					res += 2*osad;
					reqp[seq[i].b]->erase(r);
					g[react[r].a] -= osad;	
					g[react[r].b] -= osad;	
				}
				else
				{
					reqp[seq[i].b]->insert(r);	
				}
			}	
		}
		else
		{
			for(int r : *reqp[seq[i].b])
			{
				if(reqp[seq[i].a]->find(r) != reqp[seq[i].a]->end())
				{
					int osad = min(g[react[r].a], g[react[r].b]);
					res += 2*osad;
					reqp[seq[i].a]->erase(r);
					g[react[r].a] -= osad;	
					g[react[r].b] -= osad;	
				}
				else
				{
					reqp[seq[i].a]->insert(r);	
				}
			}
			reqp[seq[i].b] = reqp[seq[i].a];		
		}
	}
	
	printf("%lld\n", res);
	//system("pause");
	return 0;
}