#include<bits/stdc++.h>
#define int long long
using namespace std;
const int maxn = 2e5 + 10;
vector<int> adj[maxn];
int n, m, in[maxn], out[maxn], cnt = 0;
int a[maxn];
vector<int> x;
void dfs(int u, int p) {
in[u] = ++cnt;
x.push_back(u);
for(auto v : adj[u]) {
if(v == p) continue;
dfs(v, u);
}
out[u] = cnt;
}
int dp[maxn][510];
struct st{
int l, r, c;
};
bool cmp(st a, st b) {
return a.r < b.r;
}
st d[maxn];
signed main () {
cin >> n >> m;
int root = 0;
for(int i = 1; i <= n; i++) {
int v, c; cin >> v >> c;
if(v == 0) {
root = i;
continue;
}
adj[i].push_back(v);
adj[v].push_back(i);
a[i] = c;
}
x.push_back(0);
dfs(root, -1);
for(int i = 1; i <= n; i++) {
d[i] = {in[i], out[i], a[i]};
}
for(int i = 0; i <= n + 1; i++) {
for(int j = 1; j <= m; j++) dp[i][j] = -1e18;
}
for(int i = x.size() - 1; i >= 0; i--) {
int t = x[i];
for(int j = 1; j <= m; j++) {
dp[i][j] = max(dp[i][j], dp[i + 1][j]);
dp[i][j] = max(dp[i][j], dp[out[t] + 1][j - 1] + a[t]);
}
}
cout << dp[1][m];
}
