#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define srep(i,s,t) for (int i = s; i < t; ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
using namespace std;
typedef long long int ll;
typedef pair<int,int> P;
#define yn {puts("YES");}else{puts("NO");}
#define MAX_N 200005

int main() {
    int n; cin >> n;
    string s[n];
    rep(i,n) cin >> s[i];
    int d[26][26];
    rep(i,26){
        rep(j,26){
            d[i][j] = 0;
        }
    }
    rep(i,n){
        int start = s[i][0] - 'a';
        int now = start;
        rep(j,s[i].size()){
            int next = s[i][j] - 'a';
            if(next < now){
                now = -1;
                break;
            }
            now = next;
        }
        if(now == -1) continue;
        if(start == now) d[start][now] += s[i].size();
        else d[start][now] = max(d[start][now], (int)s[i].size());
    }
    int dp[26] = {};
    int ans = 0;
    rep(i,26){
        drep(j,26){
            if(j < i) break;
            dp[j] = max(dp[j], dp[i] + d[i][j]);
            ans = max(ans, dp[j]);
        }
    }
    cout << ans << endl;
    return 0;
}