#include <bits/stdc++.h>
using namespace std;
int en[200001];
vector<int> adj[200001];
long long cost[200001];
int n,m;int timer = 0;
vector<int> euler;
void dfs(int i,int pr){
++timer;
euler.push_back(i);
for(auto j:adj[i]){
if(j==pr)continue;
dfs(j,i);
}
en[i] = timer;
}
long long dp[2001][501];
long long solve(int i,int rem){
if(i==n)return (rem==0?0:-1e18);
if(dp[i][rem]!=-1)return dp[i][rem];
long long c1 = solve(i+1,rem);
if(rem)c1 = max(c1,solve(en[euler[i]],rem-1)+cost[euler[i]]);
return dp[i][rem] = c1;
}
signed main(){
//ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
cin>>n>>m;
int ro = 0;
for(int i = 0;i<n;i++){
int a,b;
cin>>a>>b;
cost[i+1] = b;
if(a==0)ro = i+1;
else{
adj[a].push_back(i+1);
adj[i+1].push_back(a);
}
}
dfs(ro,0);
memset(dp,-1,sizeof dp);
cout<<solve(0,m)<<"\n";
}
