#include <bits/stdc++.h>
using namespace std;
int a[200007];
int dp[200007][507];
int k;
vector<int> synowie[200007];
void dfs(int s, int ojc)
{
if (ojc != -1)
{
for (int i = 1; i <= k; i++)
{
dp[s][i] = dp[ojc][i];
}
}
for (auto x : synowie[s])
{
dfs(x, s);
}
if (ojc != -1)
{
for (int i = k; i >= 1; i--)
{
dp[ojc][i] = max(dp[ojc][i], dp[s][i]);
if (dp[ojc][i - 1] >= 0)
{
dp[ojc][i] = max(dp[ojc][i], dp[ojc][i - 1] + a[s]);
}
}
}
else
{
dp[s][1] = max(dp[s][1], a[1]);
}
/*cout << s << endl;
for(int i = 0; i <= k; i++)
{
cout << dp[s][i] << " ";
}
cout << endl;*/
}
int main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
int n, x;
cin >> n >> k;
for (int i = 0; i <= n + 3; i++)
{
for (int j = 1; j <= k + 2; j++)
{
dp[i][j] = -1;
}
}
int wh = -1;
for (int i = 1; i <= n; i++)
{
cin >> x;
if(x != 0)
{
synowie[x].push_back(i);
}
else
{
wh = i;
}
cin >> a[i];
}
dfs(wh, -1);
cout << dp[wh][k] << endl;
return 0;
}
