#include <bits/stdc++.h>
#define LL long long

using namespace std;

unordered_set<string> st;
string s[100005];

void solve()
{
    int n;

    cin >> n;
    for (int i = 1; i <= n; i++)
        cin >> s[i];

    auto cmp = [](string &l, string &r)
    {
        return l.length() < r.length();
    };
    sort(s + 1, s + n + 1, cmp);

    string ans = "";
    for (int i = 1; i <= n; i++)
        if (s[i].length() <= 1 || st.count(s[i].substr(0, s[i].length() - 1)) && st.count(s[i].substr(1, s[i].length() - 1)))
        {
            ans = s[i];
            st.insert(s[i]);
        }
    cout << ans.length() << "\n";
}

int main()
{
    ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);

    int tt = 1;
    //cin >> tt;
    while (tt--)
        solve();
}