#include <bits/stdc++.h>
using namespace std;
#define dbgs(x) cerr << (#x) << " --> " << (x) << ' '
#define dbg(x) cerr << (#x) << " --> " << (x) << endl
#define foreach(i,x) for(type(x)i=x.begin();i!=x.end();i++)
#define FOR(ii,aa,bb) for(int ii=aa;ii<=bb;ii++)
#define ROF(ii,aa,bb) for(int ii=aa;ii>=bb;ii--)
#define type(x) __typeof(x.begin())
#define orta (bas + son >> 1)
#define sag (k + k + 1)
#define sol (k + k)
#define pb push_back
#define mp make_pair
#define nd second
#define st first
#define endl '\n'
typedef pair < int ,int > pii;
typedef long long ll;
const long long linf = 1e18+5;
const int mod = (int) 1e9 + 7;
const int logN = 17;
const int inf = 1e9;
const int N = 2e5 + 5;
int w[N], val[N], n, m, x, y, start[N], finish[N], T, dp[N][501], root, p[N];
vector< int > v[N];
int dfs(int node) {
start[node] = ++T;
w[T] = node;
foreach(it, v[node])
dfs(*it);
finish[node] = T;
}
int main() {
scanf("%d %d", &n, &m);
FOR(i, 1, n) {
scanf("%d %d", &p[i], &val[i]);
if(!p[i]) root = i;
else v[p[i]].pb(i);
} dfs(root);
FOR(i, 0, m) dp[n+1][i] = -inf;
ROF(i, n, 1)
FOR(j, 0, m)
dp[i][j] = max(dp[i+1][j], (j != 0) * (dp[finish[w[i]] + 1][j-1] + val[w[i]]));
cout << dp[1][m] << endl;
return 0;
}
