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


#define DEBUG(x)
#define DEBUG2(x)
#define DEBUG3(x)


#define MAXF 400011
#define MAXR 500011
#define BLACK 1

struct OpFio {
    //Find-Union
    int parent;
    int rank;
    //Tree
    int ancestor;
    int color;
    int l,p;
    //Fio
    int waga;
    int cojest;
};

struct Reag {
    int a,b;
    int ancestor;
};
struct ReagZ {
    int v;
    int reag;
};

bool cmp(const Reag& a,const Reag& b) {
    return a.ancestor < b.ancestor;
}

OpFio opFio[MAXF];
Reag reag[MAXR];
vector<ReagZ> reagF[MAXF];

int n,m,k,op_ile, end_ile;

void printT(int r, int ile = 0) {
    if(r<=0) return;
    for(int i=0;i<ile;i++) cout << " ";
    cout << "r: " << r << " (p:" << opFio[r].parent << " r:" << opFio[r].rank << ")"
            " [a:" << opFio[r].ancestor << " c:" << opFio[r].color <<"]" <<
            " {w:" << opFio[r].waga << " j:" << opFio[r].cojest << "}\n";
    printT(opFio[r].l,ile+3);
    printT(opFio[r].p,ile+3);
}
void printR(){
    for(int i=0;i<k;i++) {
        cout << "reag: " << i << " a: " << reag[i].a << " b: " << reag[i].b << " w: " <<reag[i].ancestor <<"\n";
    }
}



void MakeSet(int x) {
    opFio[x].parent = x;
    opFio[x].rank = 0;
}

int Find(int x) {
    if(opFio[x].parent == x)
       return x;

    opFio[x].parent = Find(opFio[x].parent);
    return opFio[x].parent;
}

void Union(int x, int y) {
    int xRoot = Find(x);
    int yRoot = Find(y);
    if(opFio[xRoot].rank > opFio[yRoot].rank) {
        opFio[yRoot].parent = xRoot;
    } else if(opFio[xRoot].rank < opFio[yRoot].rank) {
        opFio[xRoot].parent = yRoot;
    } else if(xRoot != yRoot) {
        opFio[yRoot].parent = xRoot;
        opFio[xRoot].rank = opFio[xRoot].rank + 1;
    }
}

void TarjanOLCA(int u) {
     MakeSet(u);
     opFio[u].ancestor = u;
     int v = opFio[u].l;
     if(v>0) {
         TarjanOLCA(v);
         Union(u,v);
         opFio[Find(u)].ancestor = u;
     }
     v = opFio[u].p;
     if(v>0) {
         TarjanOLCA(v);
         Union(u,v);
         opFio[Find(u)].ancestor = u;
     }
     opFio[u].color = BLACK;
     for(vector<ReagZ>::iterator it = reagF[u].begin();it!=reagF[u].end();it++) {
         if(opFio[it->v].color == BLACK) {
             reag[it->reag].ancestor = opFio[Find(it->v)].ancestor;
         }
     }
}

int main() {

    scanf("%d %d %d",&n,&m,&k);
    for(op_ile=1;op_ile<=n;op_ile++) {
        scanf("%d ", &opFio[op_ile].waga);
        opFio[op_ile].cojest=op_ile;
    }
    for(int i=0;i<m;i++) {
        int a,b;
        scanf("%d %d", &a,&b);
        opFio[op_ile].l = opFio[a].cojest;
        opFio[op_ile].p = opFio[b].cojest;
        opFio[b].cojest = op_ile;
        opFio[a].cojest = -1;
        op_ile++;
    }

    end_ile = op_ile;
    int b,a = 0;
    for(int i=1;i<=n;i++) {
        if(opFio[i].cojest > 0) {
            if(a <= 0) {
                a = i;
            } else {
                b=i;
                opFio[op_ile].l = opFio[a].cojest;
                opFio[op_ile].p = opFio[b].cojest;
                opFio[b].cojest = op_ile;
                opFio[a].cojest = -1;
                op_ile++;
                a = b;
            }
        }
    }


    for(int i=0;i<k;i++) {
        int a,b;
        scanf("%d %d", &a,&b);
        reag[i].a = a;
        reag[i].b = b;
        ReagZ az,bz;
        az.v = b; bz.v = a;
        az.reag = bz.reag = i;
        reagF[a].push_back(az);
        reagF[b].push_back(bz);
    }
    TarjanOLCA(op_ile-1);
    DEBUG(printT(op_ile-1));
    DEBUG(printR());
    stable_sort(&reag[0], &reag[k], cmp);
    DEBUG2(cout << "sorted:\n");
    DEBUG2(printR());

    long long sum = 0;
    for(int i=0;i<k;i++) {
        if(0< reag[i].ancestor && reag[i].ancestor < end_ile) {
            int a,b,abmin;
            a = reag[i].a; b = reag[i].b;
            abmin = min(opFio[a].waga,opFio[b].waga);
            opFio[a].waga -= abmin;
            opFio[b].waga -= abmin;
            sum+=2*abmin;
        }
    }
    cout << sum << "\n";

	return 0;
}