#define taskname "BIOCHIP"
#include <bits/stdc++.h>
using namespace std;
const int maxn = 2e5 + 1;
vector<int> adj[maxn];
int v[maxn], a[maxn], out[maxn], n, m, root, tme = 1;
int dp[maxn][501];
/**
* a[i] = x: the value at time i is equal to x
* out[i] = t: at the exit time i, enter time is t
* dp[i][j]: choose j segments at exit time i
**/
void DFS(int u)
{
int t = tme;
for (int v: adj[u]) DFS(v);
a[tme] = v[u];
out[tme++] = t;
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(nullptr); cout.tie(nullptr);
//freopen(taskname".inp", "r", stdin);
//freopen(taskname".out", "w", stdout);
cin>>n>>m;
for (int i=1, x; i<=n; i++)
{
cin>>x>>v[i];
adj[x].emplace_back(i);
}
DFS(0);
for (int i=0; i<=n; i++) for (int j=1; j<=m; j++) dp[i][j] = -1e9;
for (int i=1; i<=n; i++)
for (int j=1; j<=m; j++)
dp[i][j] = max(dp[i-1][j], dp[out[i]-1][j-1] + a[i]);
cout<<dp[n][m];
}
