#include <bits/stdc++.h>

#define F first
#define S second
#define pb push_back
#define ll long long
#define ld long double
#define pii pair <int,int>
#define endl '\n'
#define FILE "chaos"

#pragma GCC target("sse,sse2,sse3,sse3,sse4,popcnt,abm,mmx")

using namespace std;

const int mod = 1e9 + 7;
const int N = 2e5 + 5;

struct block{
    int l, r, mx, gcd;
};

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    srand(time(0));
#ifdef LOCAL
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#else
   freopen("input.txt", "r", stdin);
   freopen("output.txt", "w", stdout);
#endif
    int n, m, k;
    cin >> n >> m >> k;
    vector <int> a;
    a.pb(0);
    for (int i = 0; i < n; i++){
        int cnt;
        cin >> cnt;
        while (cnt--){
            int x;
            cin >> x;
            a.pb(x);
        }
    }
    vector <int> dp(m, 0);
    dp[0] = 0;
    vector <block> blocks;
    for (int i = 1; i <= m; i++){
        vector <block> nblocks;
        nblocks.pb({i - 1, i - 1, a[i], -1e9});
        int g = a[i];
        for (auto &x : blocks){
           g = __gcd(g, x.gcd);
           x.gcd = g;
           nblocks.pb(x);
        }
        blocks.clear();
        for (int j = 0; j < nblocks.size(); ){
            int l = nblocks[j].l, r = nblocks[j].r, mx = nblocks[j].mx, g = nblocks[j++].gcd;
            while (j < nblocks.size() && nblocks[j].gcd == g){
                l = nblocks[j].l;
                mx = max(mx, nblocks[j++].mx);
            }
            blocks.pb({l, r, g, mx});
        }
        dp[i] = -1e9;
        for (auto &x : blocks){
            if (x.l <= i - k && x.r >= i - k) x.mx = max(x.mx, dp[i - k]);
            dp[i] = max(dp[i], x.mx + x.gcd);
        }
    }
    cout << dp[m] << endl;
    return 0;
}