using static System.Math;
using System.Collections.Generic;
using System.Linq;
using System;

public class P
{
    public int start { get; set; }
    public int end { get; set; }
    public int L { get; set; }
}

public class Hello
{
    static void Main()
    {
        var n = int.Parse(Console.ReadLine().Trim());
        var ps = new List<P>();
        for (int i = 0; i < n; i++)
        {
            var s = Console.ReadLine().Trim();
            var w = getP(s);
            if (w.start != -1) ps.Add(w);
        }
        getAns(ps);
    }
    static void getAns(List<P> ps)
    {
        var n = ps.Count();
        if (n == 0) { Console.WriteLine(0); return; }
        ps = ps.OrderBy(x => x.end).ThenBy(x => x.start).ToList();
        var dp = new int[n, 27];
        for (int i = 0; i < n; i++)
            for (int j = 1; j <= 26; j++) dp[i, j] = -1;
        var w = ps[0];
        dp[0, 0] = 0;
        dp[0, w.end] = w.L;
        for (int i = 0; i < n - 1; i++)
            for (int j = 0; j <= 26; j++)
            {
                var ww = dp[i, j];
                if (ww != -1)
                {
                    dp[i + 1, j] = Max(dp[i + 1, j], ww);
                    if (ps[i + 1].start >= j)
                    {
                        var nextend = ps[i + 1].end;
                        dp[i + 1, nextend] = Max(dp[i + 1, nextend], ww + ps[i + 1].L);
                    }
                }
            }
        var ans = 0;
        for (int i = 1; i <= 26; i++)
        {
            if (dp[n - 1, i] != -1) ans = Max(ans, dp[n - 1, i]);
        }
        Console.WriteLine(ans);
    }
    static P getP(string s)
    {
        var sL = s.Length;
        var ss = s.ToCharArray();
        Array.Sort(ss);
        if (new string(ss) == s)
            return new P { start = s[0] - 'a' + 1, end = s[sL - 1] - 'a' + 1, L = sL };
        else return new P { start = -1 };
    }
}