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
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
#include <cstdio>
#include <cstdlib>

#include <algorithm>
#include <utility>
#include <vector>

static const int VERY_LARGE_NUMBER = 2 * 1000 * 1000 * 1000;

static const int MAX_N = 200 * 1000;
static const int MAX_M = 200 * 1000;
static const int MAX_K = 500 * 1000;
static const int MAX_G = 1e9;

static const int LOG_K = 20;

struct phial
{
	int substanceAmt;
	int momentOfPouring;
	int level;				//Wysokość w drzewie
	int jumps[LOG_K];
	
	inline phial() : substanceAmt(0), momentOfPouring(VERY_LARGE_NUMBER), level(0), jumps{0} {}
};

struct rule
{
	int a, b;
	int priority;
	int properPriority;
	int properiestPriority;
	
	inline rule() : a(0), b(0), priority(0), properPriority(0) {}
	
	inline bool operator<(const rule & other) const
	{
		if (properiestPriority == other.properiestPriority)
		{
			if (properPriority == other.properPriority)
				return priority < other.priority;
			return properPriority < other.properPriority;
		}
		return properiestPriority < other.properiestPriority;
	}
};

//Ilość substancji + struktura do LCA
std::vector<phial> phials;

//Zasady reagowania
std::vector<rule> rules;

//Kolejność wylewania zawartości fiolek (+ 0 na początku)
std::vector<int> ordering;

int n, m, k;

inline int traverseUp(int id, int toLevel)
{
	int j = LOG_K;
	while (j >= 0)
	{
		int jumpamt = 1 << j;
		if (phials[id].level - jumpamt >= toLevel)
			id = phials[id].jumps[j];
		
		j--;
	}
	
	return id;
}

//Zwraca LCA oraz poprzednika LCA na ścieżce z a do LCA oraz z b do LCA
void comboLCA(int a, int b, int & lca, int & pre_lca_a, int & pre_lca_b)
{
	if (phials[a].level > phials[b].level)
	{
		comboLCA(b, a, lca, pre_lca_b, pre_lca_a);
		return;
	}
	
	int proxyB = traverseUp(b, phials[a].level);
	
	//Teraz a i b są na tym samym poziomie
	if (a == proxyB)
	{
		//LCA(a, b) == a
		lca = a;
		pre_lca_a = a;
		pre_lca_b = traverseUp(b, phials[a].level + 1);
	}
	else
	{
		//LCA jest gdzieś wyżej
		int proxyA = a;
		int j = LOG_K;
		while (j >= 0)
		{
			int nextA = phials[proxyA].jumps[j];
			int nextB = phials[proxyA].jumps[j];
			if (nextA != nextB)
			{
				proxyA = nextA;
				proxyB = nextB;
			}
			
			j--;
		}
		
		lca = phials[proxyA].jumps[0];
		pre_lca_a = proxyA;
		pre_lca_b = proxyB;
	}
}

int main()
{
	scanf("%d %d %d", &n, &m, &k);
	
	if (m == 0 || k == 0)
	{
		puts("0");
		return 0;
	}
	
	phials.reserve(n + 1);
	ordering.reserve(m + 1);
	rules.reserve(k);
	
	//Wczytanie ilości substancji w probówkach
	phials.push_back(phial());
	for (int i = 1; i <= n; i++)
	{
		phial p;
		scanf("%d", &p.substanceAmt);
		phials.push_back(p);
	}
	
	//Wczytanie operacji na fiolkach
	ordering.push_back(0);
	for (int i = 1; i <= m; i++)
	{
		int a, b;
		scanf("%d %d", &a, &b);
		phials[a].jumps[0] = b;
		phials[a].momentOfPouring = i;
		ordering.push_back(a);
	}
	
	//Wczytanie reguł zachodzenia reakcji
	for (int i = 0; i < k; i++)
	{
		rule r;
		scanf("%d %d", &r.a, &r.b);
		r.priority = i;
		rules.push_back(r);
	}
	
	//Tworzymy strukturę LCA
	for (int i = 0; i <= m; i++)
	{
		//Kolejność, którą dostajemy to odwrotny porządek topologiczny
		int c = ordering[m - i];
		phials[c].level = phials[phials[c].jumps[0]].level + 1;
		for (int j = 1; j < LOG_K; j++)
			phials[c].jumps[j] = phials[phials[c].jumps[j - 1]].jumps[j - 1];
	}
	
	//Liczymy "prawdziwy priorytet" dla reakcji
	for (int i = 0; i < k; i++)
	{
		int lca, pA, pB;
		comboLCA(rules[i].a, rules[i].b, lca, pA, pB);
		
		if (lca == 0)
		{
			//Reagenty w zasadzie nigdy nie trafią do jednej fiolki
			//Unieważniamy tą zadadę
			rules[i].a = 0;
			rules[i].b = 0;
			continue;
		}
		
		if (rules[i].a == lca)
			rules[i].properPriority = phials[pB].momentOfPouring;
		else if (rules[i].b == lca)
			rules[i].properPriority = phials[pA].momentOfPouring;
		else
			rules[i].properPriority = std::max(phials[pA].momentOfPouring, phials[pB].momentOfPouring);
		
		rules[i].properiestPriority = phials[lca].momentOfPouring;
	}
	
	//Sortujemy względem kolejności stosowania zasad
	std::sort(rules.begin(), rules.end());
	
	//Wykonujemy zasady na fiolkach
	long long int sedimentAmt = 0;
	for (const rule & r : rules)
	{
		int reactedAmt = std::min(phials[r.a].substanceAmt, phials[r.b].substanceAmt);
		
		phials[r.a].substanceAmt -= reactedAmt;
		phials[r.b].substanceAmt -= reactedAmt;
		sedimentAmt += 2 * reactedAmt;
	}
	
	printf("%lld\n", sedimentAmt);
	
	return 0;
}