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#include <cstdio>
#include <vector>
#include <utility>
#include <algorithm>
using namespace std;

#define st first
#define nd second

const int N = 200005;

vector <pair<int,int> > zap[N];
int ojc[2*N][20], n;
int G[N], lev[2*N], tab[N], fu[2*N];

int fuf(int a)
{
	if (fu[a]==a) return a;
	fu[a] = fuf( fu[a] );
	return fu[a];
}
void fuu(int a,int b)
{
	fu[ fuf(a) ] = fuf(b);
}

bool cmp(int a,int b)
{
//	if (lev[a] == lev[b]) return a<b;
	return lev[a] > lev[b];
}

int level(int a)
{
	if (ojc[a][0]==a) return 0;
	if (lev[a]) return lev[a];
	lev[a] = level( ojc[a][0] ) + 1;
	return lev[a];
}

int ojciec(int a,int k)
{
	for (int i=18;i>=0;i--)
		if ( (1<<i)&k ) a = ojc[a][i];
	return a;
}

int lca(int a,int b)
{
	if ( lev[a] > lev[b] ) swap(a,b);
	b = ojciec(b, lev[b] - lev[a] );
	if (a==b) return a;
	for (int i=18;i>=0;i--)
		if (ojc[a][i] != ojc[b][i])
		{
			a = ojc[a][i];
			b = ojc[b][i];
		}
	if (ojc[a][0]==ojc[b][0]) return ojc[a][0];
	return n;
}

long long int wynik;

int main()
{
	int m,k,a,b,x;
	scanf("%d%d%d",&n,&m,&k);
	for (int i=1;i<=n;i++) scanf("%d",&G[i] );
	for (int i=1;i<=n+m;i++) ojc[i][0] = fu[i]=i;
	for (int i=1;i<=m;i++)
	{
		scanf("%d%d",&a,&b);
		ojc[ fuf(a) ][0] = ojc[ fuf(b) ][0] = n+i;
		fuu( a, n+i );
		fuu( b, n+i ); 
	}
	for (int z=1;z<19;z++)
		for (int i=1;i<=n+m;i++)
			ojc[i][z] = ojc[ ojc[i][z-1] ][z-1];
	for (int i=1;i<=n+m;i++) level(i);
	for (int i=0;i<k;i++)
	{
		scanf("%d%d",&a,&b);
//		printf("lca %d %d - %d\n",a,b,lca(a,b) );
		zap[ lca(a,b) - n ].push_back( make_pair(a,b) );
	}
	for (int i=0;i<n;i++) tab[i]= n+i+1;
	sort( tab, tab+n, cmp);
	for (int i=0;i<n;i++)
	{
		a = tab[i] - n;
		for (int z=0;z<zap[ a ].size();z++)
		{
			x = min( G[ zap[ a ][z].first ], G[ zap[ a ][z].second ] );
			wynik += x * 2;
			G[ zap[ a ][z].first ] -= x;
			G[ zap[ a ][z].second ] -= x;
		}
	}
	printf("%lld\n",wynik);
}