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

#ifdef DEBUG
auto &operator<<(auto &o, pair<auto, auto> p) {
    return o << "(" << p.first << ", " << p.second <<")";
}
auto operator<<(auto &o, auto x)-> decltype(x.end(), o) {
    o << "{";int i = 0;
    for(auto e : x) o << ", "+!i++<<e;
    return o <<"}";
}
#define debug(x...) cerr << "["#x"]: ",[](auto...$){((cerr<<$<<"; "),...)<<endl;}(x)
#else
#define debug(...) {}
#endif

#define int long long
#define all(x) x.begin(), x.end()
#define sz(x) (int)(x).size()
#define pb push_back
#define fi first
#define se second
typedef pair <int, int> pii;

constexpr int N = 1e6+7;
vector <int> G[N];
int layer[N];
int odw[N];
int add[N];
int rem[N];

void dfs(int v, int l) {
    odw[v] = true;
    for (auto u : G[v]) {
        dfs(u, l);
    }
    if (G[v].empty()) {
        add[l]++;
        rem[layer[v]]++;
    }
}

void test() {
    debug("TC______________________");
    int k, n1; cin>>k>>n1;
    int llb = 0;
    int elem = n1;
    for (int i=1; i<k; ++i) {
        int n; cin>>n; 
        for (int j=0; j<n; ++j) {
            elem++;
            int pr; cin>>pr;
            if (pr > 0) {
                G[llb + pr].push_back(elem);
            }
            layer[elem] = i;
        }
        llb = n1;
        n1 += n;
    }

    for (int i=1; i<=n1; ++i) {
      // debug(G[i]);
      if (!odw[i]) {
          dfs(i, layer[i]);
      }
    }

    int cur = 0;
    int mx = 0;

    for (int i=0; i<k; ++i) {
        cur += add[i];
        mx = max(mx, cur);
        cur -= rem[i];
    }

    cout<<mx<<'\n';
}

signed main() {
  ios_base::sync_with_stdio(0); cin.tie(0);
  int t = 1;
  while (t--) {
    test();
  }
}