#include<bits/stdc++.h>
using namespace std;
using ll = long long int;
using ld = long double;
#define pow(n,m) powl(n,m)
#define sqrt(n) sqrtl(n)
const ll MAX = 5000000000000000000;
const ll MOD = 0;
void randinit(){srand((unsigned)time(NULL));}
int main(){
    ll N;
    cin >> N;
    vector<string> S(N);
    for(ll i = 0;i < N;i++) cin >> S[i];
    vector<tuple<ll,ll,ll>> T; //end,start

    for(ll i = 0;i < N;i++){
        bool ok = 1;
        for(ll j = 0;j < S[i].size() - 1;j++) if(S[i][j] > S[i][j + 1]) ok = 0;
        if(ok){
            char c_min = 'z',c_max = 'a';
            for(ll j = 0;j < S[i].size();j++){
                c_min = min(c_min,S[i][j]);
                c_max = max(c_max,S[i][j]);
            }
            T.emplace_back(make_tuple(c_max - 'a',c_min - 'a',S[i].size()));
        }
    }

    sort(T.begin(),T.end());
    vector<vector<ll>> DP(T.size() + 1,vector<ll>(26,0));
    for(ll i = 0;i < T.size();i++){
        DP[i + 1][get<0>(T[i])] = max(
            DP[i + 1][get<0>(T[i])],
            DP[i][get<1>(T[i])] + get<2>(T[i])
        );
        for(ll j = 0;j < 26;j++) DP[i + 1][j] = max(DP[i + 1][j],DP[i][j]);
        for(ll j = 0;j < 25;j++) DP[i + 1][j + 1] = max(DP[i + 1][j + 1],DP[i + 1][j]);
    }
    cout << DP[T.size()][25] << endl;
}