import sys
def add(a,b):
    global idx
    e[idx] = b
    ne[idx] = h[a]
    h[a] = idx
    idx += 1

def dfs(u):
    f[u][1] = happy[u]

    i = h[u]
    while i != -1:
        j = e[i]
        dfs(j)

        f[u][1] += f[j][0]
        f[u][0] += max(f[j][0],f[j][1])
        i = ne[i]

if __name__=='__main__':
    #解决爆栈问题
    limit = 10000
    sys.setrecursionlimit(limit)

    n = int(input())
    N = 6010
    happy = [0]*N
    h, e, ne, idx = [-1]* N, [0]* N, [0]* N, 0
    f = [[0]*2 for i in range(N)]
    has_father = [False]*N


    for i in range(1,n+1):
        happy[i] = int(input())

    for i in range(n-1):
        a,b = map(int,input().split())
        add(b,a)
        has_father[a] = True

    root = 1
    while has_father[root]: root += 1

    dfs(root)

    print(max(f[root][0],f[root][1]))