#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

struct Item {
    int power;
    vector<int> bonus;
};

bool compare(const Item& a, const Item& b) {
    return a.power > b.power;
}

int main() {
    int n, k;
    cin >> n >> k;

    vector<Item> items(n);
    for (int i = 0; i < n; i++) {
        cin >> items[i].power;
        items[i].bonus.resize(items[i].power);
        for (int j = 0; j < items[i].power; j++) {
            cin >> items[i].bonus[j];
        }
    }

    sort(items.begin(), items.end(), compare);

    vector<int> dp(k + 1, 0);
    for (int i = 0; i < n; i++) {
        for (int j = k; j >= items[i].power; j--) {
            for (int l = 0; l < items[i].power; l++) {
                dp[j] = max(dp[j], dp[j - items[i].power + l] + items[i].bonus[l]);
            }
        }
    }

    cout << dp[k] << endl;

    return 0;
}