BUS

#include <iostream>
#include <algorithm>
#include <numeric>
#include <set>
#include <queue>
#include <stack>
#include <vector>
#include <climits>
using namespace std;
int n, m, k, sum = 0, tmp, t, maxCarry = 0;
vector<int> a;
void read()
{
    cin >> n >> m;
    for (int i = 1; i <= n; ++ i)
    {
        cin >> t >> k;
        maxCarry += k;
        while (k--)
        {
            cin >> tmp;
            a.push_back(max(tmp - sum, 0));
        }
        sum += t;
    }
    m = min(m, maxCarry);
}
void solve()
{
    sort(a.begin(), a.end());
    sum += a[m - 1];
    cout << sum;
}
int main()
{
   ios_base::sync_with_stdio(false);
   cin.tie(nullptr);
   read();
   solve();
}