#include <bits/stdc++.h>
using namespace std;
const int N = 2e5 + 5;
int n, m, root, p[N], a[N], dp[N][505], sub[N], in[N], out[N], timer = 1;
vector<int> g[N];
void dfs(int u, int p) {
for(int v : g[u]) {
if(v == p) continue;
dfs(v, u);
for(int i=min(m, sub[u]); i>=0; i--)
for(int j=min(m-i, sub[v]); j>=1; j--)
dp[u][i+j] = max(dp[u][i+j], dp[u][i] + dp[v][j]);
sub[u] += sub[v];
}
sub[u]++;
dp[u][1] = max(dp[u][1], a[u]);
}
void dfs2(int u, int p) {
in[u] = timer++;
for(int v : g[u]) if(v ^ p) dfs2(v, u);
out[u] = timer - 1;
}
bool anc(int u, int v) {
return in[u] <= in[v] && out[v] <= out[u];
}
signed main() {
cin >> n >> m;
for(int i=1; i<=n; i++) {
cin >> p[i] >> a[i];
if(!p[i]) root = i;
else {
g[p[i]].push_back(i);
g[i].push_back(p[i]);
}
}
//fuck this shit
if(n <= 20) {
int ans = 0;
dfs2(root, root);
for(int s=0; s<(1<<n); s++) {
if(__builtin_popcount(s) != m) continue;
vector<int> u;
for(int i=0; i<n; i++)
if(s & (1 << i)) u.push_back(i+1);
bool ok = 1;
for(int i=0; i<m; i++)
for(int j=i+1; j<m; j++)
if(anc(u[i], u[j]) || anc(u[j], u[i])) ok = 0;
if(ok) {
int res = 0;
for(int x : u) res += a[x];
ans = max(ans, res);
}
}
cout << ans << '\n';
return 0;
}
dfs(root, root);
cout << dp[root][m] << '\n';
}
