#include <cstdio>#include <cstring>using namespace std;#define MAX_NODE_NUM 1005struct Node{ int value; int father; int next; int child; int id; int num;}node[MAX_NODE_NUM];int root_id, node_num;bool vis[MAX_NODE_NUM];int link[MAX_NODE_NUM];int original_value[MAX_NODE_NUM];void add_edge(int father, int son){ int temp = node[father].child; node[father].child = son; node[son].next = temp; node[son].father = father;}void input(){ memset(node, -1, sizeof(node)); for (int i = 0; i < node_num; i++) { scanf("%d", &node[i].value); node[i].id = i; node[i].num = 1; original_value[i] = node[i].value; } for (int i = 0; i < node_num - 1; i++) { int node_a, node_b; scanf("%d%d", &node_a, &node_b); node_a--; node_b--; add_edge(node_a, node_b); }}void merge_with_father(int id){ int father = node[id].father; node[father].value += node[id].value; node[father].num += node[id].num; node[father].id = node[id].id; int end = id; while (node[end].next != -1) end = node[end].next; node[end].next = node[id].child; while (node[end].next != -1) { end = node[end].next; node[end].father = father; } //printf("father:%dtson:%dn", father + 1, id + 1);}bool larger(int a, int b){ if (a == -1) return true; return node[a].value * node[b].num < node[b].value * node[a].num;}void work(){ memset(vis, 0, sizeof(vis)); vis[root_id] = true; while (1) { int p = -1; for (int i = 0; i < node_num; i++) if (!vis[i] && larger(p, i)) p = i; if (p == -1) break; vis[p] = true; link[node[node[p].father].id] = p; merge_with_father(p); } int temp = root_id; int ans = 0; for (int i = 1; i <= node_num; i++) { ans += i * original_value[temp]; temp = link[temp]; } printf("%dn", ans);}int main(){ while (scanf("%d%d", &node_num, &root_id), node_num | root_id) { root_id--; input(); work(); } return 0;}
