#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> pi;
typedef vector<int> vi;
#define pb push_back
#define f first
#define s second
#define mp make_pair
#define sz(x) (int)(x).size()
const int mx = 200005;
int N, M;
vi children[mx];
int x[mx];
vi dp[mx];
void genDP(int node){
dp[node] = vi{0};
for(auto u: children[node]){
genDP(u);
vi res = vi(min(M+1, sz(dp[node])+sz(dp[u])-1), 0);
for(int i = 0; i < sz(dp[node]); i++){
for(int j = 0; j < min(M+1-i, sz(dp[u])); j++){
res[i+j] = max(res[i+j], dp[node][i]+dp[u][j]);
}
}
dp[node] = res;
}
if(sz(dp[node]) < 2){
dp[node].pb(0);
}
dp[node][1] = max(dp[node][1], x[node]);
}
int main(){
cin >> N >> M;
for(int i = 1; i <= N; i++){
int p;
cin >> p >> x[i];
children[p].pb(i);
}
genDP(0);
cout << dp[0][M] << "\n";
}
