import std;

void main () {
    int N = readln.chomp.to!int;
    auto S = readln.split.to!(int[]);

    auto a = new int[](N - 1);
    auto b = new int[](N - 1);
    foreach (i; 0 .. N - 1) {
        readln.read(a[i], b[i]);
        a[i]--, b[i]--;
    }

    // ループにはならない。降順でトポロジカル順を成す
    auto graph = new int[][](N);
    foreach (i; 0 .. N - 1) {
        graph[a[i]] ~= b[i];
        graph[b[i]] ~= a[i];
    }

    auto ord = iota(N).array;
    ord.sort!((a, b) => S[b] < S[a]);

    auto dp = new long[](N);
    foreach (i; ord) {
        foreach (to; graph[i]) {
            if (S[i] < S[to]) {
                dp[i] = max(dp[i], dp[to]);
            }
        }
        dp[i] += S[i];
    }

    long ans = 0;
    foreach (i; 0 .. N) {
        ans = max(ans, dp[i]);
    }

    writeln(ans);
}

void read (T...) (string S, ref T args) {
    import std.conv : to;
    import std.array : split;
    auto buf = S.split;
    foreach (i, ref arg; args) {
        arg = buf[i].to!(typeof(arg));
    }
}