#include <bits/stdc++.h>

#define el '\n'
#define ll long long
#define ld long double

#define Beevo ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);

using namespace std;

const int N = 300 + 5, INF = 1e9;

int s[N], p[N];
int dp[N][N][N][2];
vector<int> g[N];

// cur = 1 ? removed
int solve(int u, int rem, int idx, bool cur, int par) {
    if (rem < 0)
        return -INF;

    if (idx >= g[u].size())
        return 0;

    int &ret = dp[u][rem][idx][cur];

    if (~ret)
        return ret;

    ret = 0;

    if (g[u][idx] == par)
        ret = solve(u, rem, idx + 1, cur, par);
    else {
        for (int i = 0; i <= rem; i++) {
            ret = max(ret, solve(g[u][idx], i, 0, 0, u) + solve(u, rem - i, idx + 1, cur, par));

            if (!cur)
                ret = max(ret, p[g[u][idx]] + solve(g[u][idx], i - s[g[u][idx]], 0, 1, u) + solve(u, rem - i, idx + 1, 0, par));
        }
    }

    return ret;
}

void testCase() {
    int n, k;
    cin >> n >> k;

    for (int i = 1; i <= n; i++)
        cin >> s[i] >> p[i];

    int u, v;
    for (int i = 1; i < n; i++) {
        cin >> u >> v;

        g[u].push_back(v);
        g[v].push_back(u);
    }

    memset(dp, -1, sizeof dp);

    cout << max(solve(1, k, 0, 0, 0), solve(1, k - s[1], 0, 1, 0) + p[1]);
}

signed main() {
    Beevo

    int T = 1;
//    cin >> T;

    while (T--)
        testCase();

    return 0;
}