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#include <bits/stdc++.h>
using namespace std;

typedef long long ll;

#define st first
#define nd second
#define pb push_back
#define all(a) a.begin(), a.end()
#define sz(a) int(a.size())
#define f(i, a, b) for (int i = a; i < b; i++)
#define rep(i, a) f(i, 0, a)
#define int ll
#define tv(a, x) for (auto& a : x)
#define DUZO 1000000000000000000LL
#define en "\n"
#define cn continue
using pii = pair<int, int>;
using vi = vector<int>;
using vvi = vector<vi>;
using vii = vector<pii>;

int k;
vi n;
vvi a;

bool ok(int x) {
    if (n.back() > x) return false;
    vi dp(n.back(), 1);
    for (int i = k - 1; i >= 1; i--) {
        vi ndp(n[i - 1], 0);
        rep(j, n[i]) {
            if (a[i][j]) {
                ndp[a[i][j] - 1] += dp[j];
                if (ndp[a[i][j] - 1] > x) ndp[a[i][j] - 1] = x + 1;
            }
        }
        int sm = 0;
        rep(j, n[i - 1]) {
            ndp[j] = max(ndp[j], 1LL);
            sm += ndp[j];
            if (sm > x) return false;
        }
        dp.swap(ndp);
    }
    return true;
}

void solve() {
    cin >> k;
    n.resize(k);
    a.assign(k, {});
    cin >> n[0];
    int mx = n[0];
    int sm = n[0];
    f(i, 1, k) {
        cin >> n[i];
        mx = max(mx, n[i]);
        sm += n[i];
        a[i].resize(n[i]);
        rep(j, n[i]) cin >> a[i][j];
    }
    int l = mx;
    int r = sm;
    while (r > l) {
        int mid = (l + r)/2;
        if (ok(mid)) {
            r = mid;
        } else {
            l = mid + 1;
        }
    }
    cout << l << en;
}

int32_t main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    int q = 1;
    //cin >> q;
    while (q--) {
        solve();
    }
    return 0;
}