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
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
#include<iostream>
#include<vector>
#include<utility>
#include<cassert>
using namespace std;
typedef pair<int,int> PII;
typedef vector<int> VI;
typedef vector<PII> VII;
typedef long long LL;
const int MAXN = (1<<18)+1;
const int MAXK = (1<<19)+1;
const int WHITE = 1;
const int GRAY = 2;
const int BLACK = 3;

struct Node;

struct Query {
  Node* a; 
  Node* b;
  Node* result;
  Query(Node* aa=nullptr, Node* bb=nullptr) : a(aa), b(bb), result(nullptr) {}
  Node* other(Node* n) {
    if (n == a) return b;
    return a;
  }
} _queries[MAXK];
int queryCount = 0;

struct Node {
  Node* left;
  Node* right;
  Node* parent;
  VII reactions;
  int color;
  vector<Query*> queries;
  int idx;
  Node(int i=-1, Node* l=nullptr, Node* r=nullptr) : left(l), right(r), parent(nullptr), reactions(), color(WHITE), queries(), idx(i) {}
  Node* getRepr() {
    if (parent != this) {
      parent = parent->getRepr();
    }
    return parent;
  }
  void lcaVisit() {
    color = GRAY;
    parent = this;
    if (left != nullptr) {
      left->lcaVisit();
      left->parent = this;
    }
    if (right != nullptr) {
      right->lcaVisit();
      right->parent = this;
    }
    for (Query* q : queries) {
      Node* other = q->other(this);
      if (other->color != WHITE) {
        q->result = other->getRepr();
  //      q->result->reactions.push_back(PII(q->a->idx, q->b->idx));
      }
    }
    color = BLACK;
  }
  void whiteVisit() {
    color = WHITE;
    if (left != nullptr) {
      left->whiteVisit();
    }
    if (right != nullptr) {
      right->whiteVisit();
    }
  }
  LL sedimentVisit(int* g) {
    LL result = 0;
    if (left != nullptr) {
      result += left->sedimentVisit(g);
    }
    if (right != nullptr) {
      result += right->sedimentVisit(g);
    }
    for (PII r : reactions) {
      int s = min(g[r.first], g[r.second]);
      // printf("reaction: %d %d: %d\n", r.first, r.second, s);
      g[r.first] -= s;
      g[r.second] -= s;
      result += 2 * s;
    }
    return result;
  }
};

void newQuery(Node* a, Node* b) {
  _queries[queryCount] = Query(a, b);
  a->queries.push_back(&_queries[queryCount]);
  b->queries.push_back(&_queries[queryCount]);
  queryCount++;
}

Node _nodes[2*MAXN];
int nodeCount = 0;
Node* newNode(Node* l, Node* r) {
  _nodes[nodeCount] = Node(nodeCount, l, r);
  return &_nodes[nodeCount++];
}

Node* nodes[MAXN];

void join(int a, int b) {
  nodes[b] = newNode(nodes[a], nodes[b]);
  nodes[a] = nullptr;
}

void addQuery(int c, int d) {
  newQuery(&_nodes[c], &_nodes[d]);
}

int g[MAXN];

int main() {
  int n, m, k;
  assert(3 == scanf("%d%d%d", &n, &m, &k));
  nodeCount = n;
  for (int i = 0; i < n; ++i) {
    nodes[i] = &_nodes[i];
    nodes[i]->idx = i;
    assert(1 == scanf("%d", &g[i]));
  }
  for (int i = 0; i < m; ++i) {
    int a, b;
    assert(2 == scanf("%d%d", &a, &b));
    a--, b--;
    join(a, b);
  }
  for (int i = 0; i < k; ++i) {
    int c, d;
    assert(2 == scanf("%d%d", &c, &d));
    c--, d--;
    addQuery(c, d);
  }
  LL result = 0;
  for (int i = 0; i < n; ++i) {
    if (nodes[i] != nullptr) {
      nodes[i]->lcaVisit();
      nodes[i]->whiteVisit();
    }
  }
  for (int i = 0; i < k; ++i) {
    Query* q = &_queries[i];
    // printf("lca %d %d: %d\n", q->a->idx, q->b->idx, q->result->idx);
    if (q->result != nullptr) {
      q->result->reactions.push_back(PII(q->a->idx, q->b->idx));
    }
  }
  for (int i = 0; i < n; ++i) {
    if (nodes[i] != nullptr) {
      result += nodes[i]->sedimentVisit(g);
    }
  }
  printf("%lld\n", result);
  return 0;
}