#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define ll long long
#define int long long
#define mod 1000000007
#define ld long double
#define all(x) (x).begin() , (x).end()
#define pb push_back
using namespace __gnu_pbds;
using namespace std;
template <typename T>
using ordered_set = tree<T, null_type, less_equal<T>, rb_tree_tag, tree_order_statistics_node_update>;
const ll maxn=200005;
ll n,m;
vector<vector<ll>> v(maxn);
vector<vector<ll>> dp(n+2,vector<ll>(m+2,LLONG_MIN));
vector<ll> val(maxn);
vector<ll> combine(vector<ll>& a,vector<ll>& b){
vector<ll> r(min((ll)(a.size()+b.size()-1),m+1),LLONG_MIN);
for(int i=0; i<a.size(); i++){
// if(a[i]<0) continue;
for(int j=0; j<b.size(); j++){
// if(b[i]<0) continue;
if(i+j<=m) r[i+j]=max(r[i+j],a[i]+b[j]);
}
}
return r;
}
void dfs(ll st,ll p){
if(p==0) dp[st]={0};
for(ll i:v[st]){
if(i==p) continue;
dfs(i,st);
dp[st]=combine(dp[st],dp[i]);
}
dp[st][1]=max(dp[st][1],val[st]);
}
signed main(){
cin.tie(0)->sync_with_stdio(0);
ll tt=1;
// cin >> tt;
while(tt--){
// ll n,m;
ll root;
cin >> n >> m;
dp.assign(n+2,vector<ll>(m+2,LLONG_MIN));
for(int i=0; i<n; i++){
ll x,y;
cin >> x >> y;
if(x==0) root=i+1;
v[x].pb(i+1),val[i+1]=y;
}
dfs(root,0);
cout << dp[root][m];
}
return 0;
}
