#include <bits/stdc++.h>
using namespace std;
const int maxn = 2e5 + 5;
int n, m, root, a[maxn], P[maxn], in[maxn], out[maxn], T=0, dp[maxn][505];
vector<int> G[maxn], E;
void dfs(int u) {
in[u] = T++; E.push_back(u);
for(int v : G[u]) dfs(v);
out[u] = T;
}
int main() {
cin >> n >> m;
for(int i=0; i<=n; i++)
for(int j=0; j<=m; j++) dp[i][j] = -1e9;
for(int i=1; i<=n; i++) {
cin >> P[i] >> a[i];
if(!P[i]) root = i;
else G[P[i]].push_back(i);
}
dfs(root); dp[n][0] = 0;
for(int i=n-1; i>=0; i--) {
for(int j=0; j<=m; j++) {
dp[i][j] = dp[i+1][j];
if(j) dp[i][j] = max(dp[i][j], dp[out[E[i]]][j-1] + a[E[i]]);
}
}
cout << dp[0][m] << '\n';
}
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