#include<iostream>
// #include<bits/stdc++.h>
#include<algorithm>
#include<set>
#include<map>
#include<vector>
#include<queue>
#define pb push_back
#define int long long
#define all(v) (v).begin() , (v).end()
using namespace std;
const int inf = 1e17 , N = 5e5 + 4;
int n , m ;
int x[N];
int dp[N][505];
vector<int>g[N];
void dfs(int v , int p){
for(auto it:g[v]){
if(it==p)continue;
dfs(it , v);
for(int k =1 ; k <= m ; k++){
for(int i= 0; i + k <= m ;i++){
dp[v][i+k] = max(dp[v][k] + dp[it][i] , dp[v][i+k]);
}
}
}
dp[v][1] = max(x[v] , dp[v][1]);
}
signed main(){
// freopen("d.in" , "r" , stdin);
// freopen("d.out" , "w" , stdout);
ios_base::sync_with_stdio(0) , cin.tie(0);
cin >> n >> m ;
int pr = 0;
for(int i= 1 ; i <= n ; i++){
int p ;
cin >> p >> x[i] ;
if(p == 0 )pr = i ;
g[p].pb(i);
}
dfs(pr ,0 );
cout << dp[pr][m];
}
