#include <bits/stdc++.h>

using namespace std;

#define int long long
#define mp make_pair
using hashv = pair<int, int>;

const hashv mod = mp(1e9 + 7, 998244353);
const hashv base = mp(13331, 23333);

hashv operator+(hashv a, hashv b) {
    int c1 = a.first + b.first, c2 = a.second + b.second;
    if (c1 >= mod.first) c1 -= mod.first;
    if (c2 >= mod.second) c2 -= mod.second;
    return mp(c1, c2);
}

hashv operator-(hashv a, hashv b) {
    int c1 = a.first - b.first, c2 = a.second - b.second;
    if (c1 < 0) c1 += mod.first;
    if (c2 < 0) c2 += mod.second;
    return mp(c1, c2);
}

hashv operator*(hashv a, hashv b) {
    return mp(a.first * b.first % mod.first, a.second * b.second % mod.second);
}

const int N = 1e5 + 5;
vector<hashv> p(N);

void hashStr(const string &s, vector<hashv> &v) {
    v.resize(s.size() + 1);
    for (int i = 1; i <= s.size(); i++)
        v[i] = v[i - 1] * base + mp(s[i - 1], s[i - 1]);
    return;
}

hashv getHash(int l, int r, const vector<hashv> &v) {
    if (l > r) return mp(0, 0);
    return v[r] - v[l - 1] * p[r - l + 1];
}

void init() {
    p[0] = mp(1, 1);
    for (int i = 1; i < N; i++)
        p[i] = p[i - 1] * base;
}


int32_t main() {
    ios::sync_with_stdio(false), cin.tie(nullptr);
    init();
    int n;
    cin >> n;
    vector<string> s(n);
    vector<vector<hashv>> hv(n);
    for (auto &i: s) cin >> i;
    set<hashv> vis;
    for (int i = 0; i < n; i++)
        hashStr(s[i], hv[i]), vis.insert(hv[i].back());
    int res = 0;
    for (int i = 0, len, f; i < n; i++) {
        len = s[i].size(), f = 1;
        if (len <= res) continue;
        for (int l = 1; f and l <= len; l++)
            for (int r = l; f and r <= len; r++)
                if (vis.count(getHash(l, r, hv[i])) == 0) f = 0;
        if (f) res = len;
    }
    cout << res << "\n";
    return 0;
}