#include <iostream>
#include <vector>
using namespace std;
const int N = 2e5 + 10;
const int M = 510;
int n, k, u, a[N];
int root, dp[N][2];
int in[N], out[N], cnt;
vector <int> v[N];
void DFS(int s) {
in[s] = ++cnt;
for (int z: v[s]) DFS(z);
out[s] = cnt;
}
int main() {
cin.tie(0); cout.tie(0);
ios_base::sync_with_stdio(false);
cin >> n >> k;
for (int i = 1; i <= n; ++i) {
cin >> u >> a[i];
if (u == 0) root = i;
else v[u].push_back(i);
}
DFS(root);
for (int x = 1; x <= k; ++x) {
for (int i = 1; i <= n; ++i) {
dp[out[i]][1] = max(dp[out[i]][1], dp[in[i] - 1][0] + a[i]);
}
for (int i = 1; i <= n; ++i) {
dp[i][0] = max(dp[i][1], dp[i - 1][0]);
dp[i][1] = -1e9;
}
dp[0][0] = -1e9;
}
cout << dp[n][0] << "\n";
return 0;
}
