1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
#include <cstdio>
#include <vector>
#include <algorithm>

using namespace std;

int FU[200005];

int fu( int a )
{if (FU[a]==a) return a; return FU[a]=fu(FU[a]); }

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

long long wyn;
int tt;
int G[200005];
int P[500005][2];
int P_odw[500005];
int IL[200005];
vector<int> KR[200005];
vector<int> PROC[200005];
vector<int> V[200005];

void DFS( int w )
{
    for ( int i=0; i<(int)V[w].size(); i++ )
        {
            int v = V[w][i];
            if ( P_odw[ v ] == tt )
               {
                   int _s;
                   if ( w == P[ v ][0] )
                       _s = P[ v ][1];
                      else _s = P[ v ][0];
                   PROC[ fu(_s) ].push_back( v );
               } else P_odw[ v ] = tt;
        }
    
    for ( int i=0; i<(int)KR[w].size(); i++ )
        {
            int w2 = KR[w][i];
            
            DFS( w2 );
            
            sort( PROC[w].begin(), PROC[w].end() );
            for ( int j=0; j<(int)PROC[w].size(); j++ )
                {
                    int p = PROC[w][j];
                    int a = P[p][0];
                    int b = P[p][1];
                    int c = min( G[a], G[b] );
                    wyn  += 2*c;
                    G[a] -= c;
                    G[b] -= c;
                }
            PROC[w].clear();
            
            un( w2, w );
        }
}

int main()
{
    int n,m,k;
    scanf( "%d%d%d", &n, &m, &k );
    
    for ( int i=0; i<n; i++ )
        {
            scanf( "%d", G+i );
            FU[i]=i; IL[i]=0;
        }
    for ( int i=0; i<m; i++ )
        {
            int a,b;
            scanf( "%d%d", &a, &b );
            a--; b--;
            KR[ b ].push_back(a);
            IL[a]++;
        }
    
    for ( int i=0; i<k; i++ )
        {
            int a,b;
            scanf( "%d%d", &a, &b );
            a--; b--;
            P[i][0]=a; P[i][1]=b;
            V[a].push_back( i );
            V[b].push_back( i );
            P_odw[ i ] = -1;
        }
    
    wyn=0;
    for ( int i=0; i<n; i++ ) if ( !IL[i] ) {tt=i+1; DFS( i );}
    
    printf("%lld\n",wyn);
    
    return 0;
}