#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
int main(void) {
    ll n, k;
    scanf("%lld%lld", &n, &k);
    vector<ll> par(n+1), cap(n+1), cur(n+1);
    ll ans = k;
    for (int i = 1; i <= n; ++i) {
        scanf("%lld%lld%lld", &par[i], &cap[i], &cur[i]);
        ll at = i, cost = 0, water = 0;
        while (at && cost < ans) {
            ll add = max(0LL, cap[at]-cur[at]-water);
            cost += add;
            water += add + cur[at];
            at = par[at];
        }
        cost += max(0LL, k-water);
        ans = min(ans, cost);
    }
    printf("%lld\n", ans);
}