#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);
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], dp[u][i] + dp[v][j]);
sub[u] += sub[v];
}
sub[u]++;
dp[u][1] = max(dp[u][1], a[u]);
}
signed main() {
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';
}
