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
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
#include <iostream>
#include <cstdio>
#include <string>
#include <vector>
#include <set>
#include <map>
#include <queue>
#include <cmath>
#include <algorithm>
#include <sstream>
#include <stack>
#include <cstring>
#include <iomanip>
#include <ctime>
using namespace std;
#define pb push_back
#define INF 1001001001
#define FOR(i,n) for(int (i)=0;(i)<(n);++(i))
#define FORI(i,n) for(int (i)=1;(i)<=(n);++(i))
#define mp make_pair
#define pii pair<int,int>
#define ll long long
#define vi vector<int>
#define SZ(x) ((int)((x).size()))
#define fi first
#define se second
#define wez(n) int (n); scanf("%d",&(n));
#define wez2(n,m) int (n),(m); scanf("%d %d",&(n),&(m));
#define wez3(n,m,k) int (n),(m),(k); scanf("%d %d %d",&(n),&(m),&(k));
inline void pisz(int n) { printf("%d\n",n); }
template<typename T,typename TT> ostream& operator<<(ostream &s,pair<T,TT> t) {return s<<"("<<t.first<<","<<t.second<<")";}
template<typename T> ostream& operator<<(ostream &s,vector<T> t){FOR(i,SZ(t))s<<t[i]<<" ";return s; }
#define DBG(vari) cerr<<#vari<<" = "<<(vari)<<endl;
#define ALL(t) t.begin(),t.end()
#define FOREACH(i,t) for (__typeof(t.begin()) i=t.begin(); i!=t.end(); i++)
#define TESTS wez(testow)while(testow--)
#define REP(i,a,b) for(int (i)=(a);(i)<=(b);++i)
#define REPD(i,a,b) for(int (i)=(a); (i)>=(b);--i)
#define REMAX(a,b) (a)=max((a),(b));
#define REMIN(a,b) (a)=min((a),(b));
#define IOS ios_base::sync_with_stdio(0);

namespace lca {
#define N 400007
#define LOGN 19
int n, ojc[N], // input
pos[N], anc[LOGN+1][N]; // temp

int getPos(int u) {
   if (pos[u] == -1) pos[u] = getPos(ojc[u])+1;
   return pos[u];
}

void init(int root) {
   FORI(i,n) anc[0][i] = ojc[i];
   FORI(i,n) pos[i] = -1;
   pos[root] = 0;
   FORI(i,n) if (pos[i] == -1) getPos(i);
   FORI(i,LOGN) FORI(j,n) anc[i][j] = anc[i-1][anc[i-1][j]];
}

int lca (int u, int v) {
   if (pos[u] < pos[v]) swap(u,v);
   int diff = pos[u] - pos[v];
   REPD(k,LOGN,0) if ((1<<k) <= diff) {
      diff -= 1<<k;
      u = anc[k][u];
   }
   // teraz sa w tej samej odleglosci od roota
   if (u==v) return u;
   REPD(k,LOGN,0) if (anc[k][u] != anc[k][v]) {
      u = anc[k][u];
      v = anc[k][v];
   }
   return ojc[u];
}
};


const int max_size=100000;
char buf[max_size];
int buf_size=0,pos=0;

#define getbuf() buf_size=fread(buf,1,max_size,stdin)
#define get(tok) {if (pos>=buf_size) { if (feof(stdin)) tok=0;	else { getbuf();pos=0; tok=buf[pos++];}}else tok=buf[pos++];}
#define in(v) {int tok;get(tok);while (tok==' ' || tok=='\n')get(tok);v=tok-'0';get(tok);while(tok>='0' && tok<='9'){v*=10;v+=(tok-'0');get(tok);}}

vi children[N];

void add (int child, int parent) {
   //DBG(mp(child,parent))
   lca::ojc[child] = parent;
   children[parent].pb(child);
}

vector<pii> reakcje[N];
int gramow[N];
ll res;

void dfs (int v) {
   FOREACH(x,children[v]) dfs(*x);
   FOREACH(r,reakcje[v]) {
      const int ci = r->fi, di = r->se;
      const int osad = min(gramow[ci], gramow[di]);
      gramow[ci] -= osad;
      gramow[di] -= osad;
      res += osad;
      //DBG(v)
      //DBG(mp(mp(ci,di), osad))
   }
}

int cur[N];
bool dead[N];

int main () {
   int substancji, krokow, reakcji;
   in(substancji); in(krokow); in(reakcji);
   FORI(i,substancji) in(gramow[i]);
   FORI(i,substancji) cur[i] = i;
   int last = substancji;
   FORI(u,krokow) {
      int ai, bi;
      in(ai); in(bi);
      dead[ai] = 1;
      ++last;
      add(cur[ai], last);
      add(cur[bi], last);
      cur[bi] = last;
   }
   ++last;
   int root = last;
   FORI(i,substancji) if (!dead[i]) add(cur[i], root);
   lca::n = last;
   lca::init(root);
   
   FORI(u,reakcji) {
      int ci, di;
      in(ci); in(di);
      int LCA = lca::lca(ci,di);
      if (LCA != root) reakcje[LCA].pb(mp(ci,di));
   }
   
   res = 0;
   dfs(root);
   cout << 2 * res;
}