#include <bits/stdc++.h>
using namespace std;
const int N = 2e5 + 5;
int n, m, root, p[N], a[N], dp[N][505], sub[N];
vector<int> g[N];
void dfs(int u, int p) {
for (int v : g[u]) {
if (v == p) continue;
dfs(v, u);
int temp[505];
memcpy(temp, dp[u], sizeof(dp[u]));
for (int i = min(m, sub[u]); i >= 0; i--) {
for (int j = min(m - i, sub[v]); j >= 0; j--) {
dp[u][i + j] = max(dp[u][i + j], temp[i] + dp[v][j]);
}
}
sub[u] += sub[v];
}
sub[u]++;
dp[u][1] = max(dp[u][1], a[u]); // Take current node as a single selection
}
signed main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
cin >> n >> m;
for (int i = 1; i <= n; i++) {
cin >> p[i] >> a[i];
if (!p[i]) {
root = i;
} else {
g[p[i]].push_back(i);
g[i].push_back(p[i]);
}
}
dfs(root, root);
cout << dp[root][m] << '\n';
return 0;
}
