#include <stdio.h>
#include <stdlib.h>
#include <limits.h>

int n, i, v, s, e;

typedef struct nod {
    long int val;
    struct nod *c;
    struct nod *s;
} nod;

nod *nodes[16001];
unsigned int gsum = INT_MIN;

inline int max(int a, int b) {
    return a > b ? a : b;
}

unsigned long long solve(nod *root) {
    int ms = 0;

    if (root == NULL) return 0;

    nod *c = root->c;
    while (c) {
        ms += max(solve(c), 0);
        c = c->s;
    }
    
    gsum = max(ms + root->val, gsum);
    return max(ms + root->val, 0);
}

int main() {
    nod *x;
    unsigned int esum = 0;
    FILE *fi, *fo;
    fi = freopen("asmax.in", "r", stdin);
    fo = freopen("asmax.out", "w", stdout);
    scanf("%d", &n);
    for(i=1;i<=n;i++) {
        scanf("%d", &v);
        x = (nod*) malloc(sizeof(nod));
        x->val = v;
        nodes[i] = x;
    }
    for(i = 1; i < n; i++) {
        scanf("%d %d", &s, &e);
        nodes[e]->s = nodes[s]->c;
        nodes[s]->c = nodes[e];
        esum += e;
    }
    solve(nodes[(n * (n + 1))/2 - esum]);
    printf("%d\n", gsum);
    fclose(fi);
    fclose(fo);
    return 0;
}