#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int MXN = 200 * 1000 + 3;
const int MXM = 503;
int dp[MXN][MXM], a[MXN];
vector<int> g[MXN];
int n, m;
void dfs(int v) {
for(int u : g[v]) {
dfs(u);
for(int i = m; i >= 0; i--)
for(int j = 0; j <= m; j++) if(i - j >= 0 && dp[v][i - j] != -1 && dp[u][j] != -1)
dp[v][i] = max(dp[v][i], dp[v][i - j] + dp[u][j]);
}
dp[v][1] = max(dp[v][1], a[v]);
}
signed main() {
std::ios::sync_with_stdio(0);
std::cin.tie(0);
cin >> n >> m;
int r = -1;
for(int p, i = 1; i <= n; i++) {
cin >> p >> a[i];
dp[i][0] = 0;
for(int j = 1; j <= m; j++)
dp[i][j] = -1;
if(p)
g[p].push_back(i);
else
r = i;
}
dfs(r);
// for(int i = 1; i <= n; i++) {
// for(int j = 1; j <= m; j++)
// cout << dp[i][j] << ' ';
// cout << '\n';
// }
cout << dp[r][m] << '\n';
return 0;
}
