#include <bits/stdc++.h>
using namespace std;
#define int long long
#define endl "\n"
#define mod 1000000007
int dp[200001][501],dp2[200001][501],leafs[200001],n,m,arr[200001];
vector <array<int,2>> v[200001];
int rt;
int solve(int last,int i,int k){
if(dp2[i][k]!=-1) return dp2[i][k];
int idx=v[last][i][0];
if(i==v[last].size()-1){
if(k>leafs[idx]) return dp2[i][k]=-1e18;
else return dp2[i][k]=dp[idx][k];
}
int ans=0;
for(int j=0;j<=min(k,leafs[idx]);j++){
ans=max(ans,solve(last,i+1,k-j)+dp[idx][j]);
}
//exit(0);
return dp2[i][k]=ans;
}
void build(int i){
if(v[i].size()==0){
leafs[i]=1;
return;
}
for(auto [j,c]:v[i]){
build(j);
leafs[i]+=leafs[j];
}
return;
}
void calc(int i){
for(auto [j,lef]:v[i]) calc(j);
for(int k=0;k<=max(1ll,leafs[i]);k++){
if(k==1) dp[i][k]=arr[i];
if(v[i].size()!=0) dp[i][k]=max(dp[i][k],solve(i,0,k));
//cout<<i<<" "<<k<<" "<<dp[i][k]<<endl;
}
memset(dp2,-1,sizeof dp2);
return;
}
signed main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
memset(dp2,-1,sizeof dp2);
cin>>n>>m;
for(int i=1;i<n;i++){
int p;
cin>>p>>arr[i];
if(p==0) rt=i;
else v[p].push_back({i,0});
}
build(rt);
for(int i=1;i<=n;i++){
for(int j=0;j<v[i].size();j++) v[i][j][1]=leafs[v[i][j][0]];
sort(v[i].begin(),v[i].end());
// cout<<i<<":"<<endl;
// for(auto [j,lef]:v[i]) cout<<j<<" "<<lef<<endl;
}
calc(rt);
cout<<dp[rt][m]<<endl;
}
