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#include<iostream>
#include<algorithm>
#include<vector>
using namespace std;
#define ll long long
#define ld long double
#define vi vector<int>
#define pb push_back
#define pii pair<int,int>
#define mp make_pair
#define st first
#define nd second
#define mini(a,b) a=min(a,(b))
#define maxi(a,b) a=max(a,(b))
#define RE(i,n) for(int i=0,_n=(n);i<_n;++i)
#define RI(i,n) for(int i=1,_n=(n);i<=_n;++i)
const int inf=1e9+5, nax=400123, pot = (1 << 20); // jakie ma być pot? iurghwouwihfhg3rouhwfjpoh3vwrowuhfdushwgoruhfsjvdoisjr

int n, ile_krokow, ile_par;
int waga[nax];
int nr_v[nax], gr[nax];
vi w[nax];
int ojc[nax], prawy[nax], lewy[nax], h[nax];
int ile_wierz;
int tr[2 * pot + 5];
int licznik;
int odw[nax];
vector<pii > event[nax];
ll RES;

void dfs(int x) {
	tr[pot + licznik] = x;
	odw[x] = licznik;
	licznik++;
	if(lewy[x] == 0) return;
	h[lewy[x]] = h[prawy[x]] = h[x] + 1;
	dfs(lewy[x]);
	tr[pot + licznik] = x;
	licznik++;
	dfs(prawy[x]);
	tr[pot + licznik] = x;
	licznik++;
}

int LCA(int a, int b) {
	a = odw[a] + pot;
	b = odw[b] + pot;
	if(a > b) swap(a, b);
	int res = tr[a];
	if(h[tr[b]] < h[res])
		res = tr[b];
	while(a < b - 1) {
		if(a % 2 == 0 && h[tr[a+1]] < h[res])
			res = tr[a+1];
		if(b % 2 && h[tr[b-1]] < h[res])
			res = tr[b-1];
		a /= 2;
		b /= 2;
	}
	return res;
}

void res_dfs(int x) {
	if(lewy[x]) {
		res_dfs(lewy[x]);
		res_dfs(prawy[x]);
	}
	RE(i, event[x].size()) {
		int a = event[x][i].st, b = event[x][i].nd;
		int m = min(waga[a], waga[b]);
		RES += 2 * m;
		waga[a] -= m;
		waga[b] -= m;
	}
}

int main()
{
	ios_base::sync_with_stdio(0);
	cin >> n >> ile_krokow >> ile_par;
	RI(i, n) cin >> waga[i];
	RI(i, n) {
		gr[i] = i;
		w[i].pb(i);
	}
	
	ile_wierz = n;
	RE(_, ile_krokow) {
		int a, b;
		cin >> a >> b;
		a = gr[a];
		b = gr[b];
		if(w[a].size() > w[b].size())
			swap(a, b);
		// 'a' wrzucamy do 'b'
		RE(i, w[a].size()) {
			w[b].pb(  w[a][i]  );
			gr[  w[a][i]   ] = b;
		}
		
		int v_a = nr_v[a], v_b = nr_v[b];
		ile_wierz++;
		lewy[ile_wierz] = v_a;
		prawy[ile_wierz] = v_b;
		ojc[v_a] = ojc[v_b] = ile_wierz;
		nr_v[b] = ile_wierz;
	}
	
	RI(i, ile_wierz) if(ojc[i] == 0)
		dfs(i);
	
	h[0] = inf;
	for(int i = pot - 1; i > 0; --i) {
		if(h[tr[2 * i]] < h[tr[2 * i + 1]])
			tr[i] = tr[2 * i];
		else
			tr[i] = tr[2 * i + 1];
	}
	
	RE(i, ile_par) {
		int a, b;
		cin >> a >> b;
		if(gr[a] == gr[b]) {
			int x = LCA(a, b);
			event[x].pb(mp(a,b));
		}
	}
	
	RI(i, ile_wierz) if(ojc[i] == 0)
		res_dfs(i);
	cout << RES << "\n";
	return 0;
}