#include <algorithm>

#include  <iterator>

#include  <iostream>

#include   <cstring>

#include   <cstdlib>

#include   <iomanip>

#include    <bitset>

#include    <cctype>

#include    <cstdio>

#include    <string>

#include    <vector>

#include     <stack>

#include     <cmath>

#include     <queue>

#include      <list>

#include       <map>

#include       <set>

#include   <cassert>

/*

⊂_ヽ

　 ＼＼ Λ＿Λ  来了老弟

　　 ＼('ㅅ')

　　　 >　⌒ヽ

　　　/ 　 へ＼

　　 /　　/　＼＼

　　 ﾚ　ノ　　 ヽ_つ

　　/　/

　 /　/|

　(　(ヽ

　|　|、＼

　| 丿 ＼ ⌒)

　| |　　) /

'ノ )　　Lﾉ

*/

using namespace std;

#define lson (l , mid , rt << 1)

#define rson (mid + 1 , r , rt << 1 | 1)

#define debug(x) cerr << #x << " = " << x << "\n";

#define pb push_back

#define pq priority_queue

typedef long long ll;

typedef unsigned long long ull;

//typedef __int128 bll;

typedef pair<ll ,ll > pll;

typedef pair<int ,int > pii;

typedef pair<int,pii> p3;

//priority_queue<int> q;//这是一个大根堆q

//priority_queue<int,vector<int>,greater<int> >q;//这是一个小根堆q

#define fi first

#define se second

//#define endl '\n'

#define boost ios::sync_with_stdio(false);cin.tie(0)

#define rep(a, b, c) for(int a = (b); a <= (c); ++ a)

#define max3(a,b,c) max(max(a,b), c);

#define min3(a,b,c) min(min(a,b), c);

const ll oo = 1ll<<;

const ll mos = 0x7FFFFFFF;  //

const ll nmos = 0x80000000;  //-2147483648

const int inf = 0x3f3f3f3f;

const ll inff = 0x3f3f3f3f3f3f3f3f; //

const int mod = 1e9+;

const double esp = 1e-;

const double PI=acos(-1.0);

const double PHI=0.61803399;    //黄金分割点

const double tPHI=0.38196601;

template<typename T>

inline T read(T&x){

    x=;int f=;char ch=getchar();

    while (ch<''||ch>'') f|=(ch=='-'),ch=getchar();

    while (ch>=''&&ch<='') x=x*+ch-'',ch=getchar();

    return x=f?-x:x;

}

inline void cmax(int &x,int y){if(x<y)x=y;}

inline void cmax(ll &x,ll y){if(x<y)x=y;}

inline void cmin(int &x,int y){if(x>y)x=y;}

inline void cmin(ll &x,ll y){if(x>y)x=y;}

/*-----------------------showtime----------------------*/

            const ll big = 1e9+;

            ll dp[],tmp[];

            string str;

int main(){

            int n;

            scanf("%d", &n);

            ll ans = ;

            rep(cc, , n){

                cin>>str;

                int len = str.length();

                int flag = ;

                for(int i=; i<len; i++) if(str[i] != str[]) flag = ;

                if(flag) {

                    int id = (str[] - 'a');

                    rep(i, , ) {

                        if(i == id) continue;

                        if(dp[i]) dp[i] = ;

                    }

                    if(dp[id]){

                        ll t = min(big, 1ll*(dp[id] + ) * len + dp[id]);

                        dp[id] = max(dp[id], t);

                    }

                    dp[id] = max(1ll*len, dp[id]);

                }

                else  {

                    rep(i, , ){

                        if(dp[i]) dp[i] = ;

                        tmp[i] = ;

                    }

                    ll e = ;char la = str[];

                    str+="A";

                    rep(i, , len){

                        if(str[i] != la){

                            int id = (int)(la - 'a');

                            tmp[id] = max(tmp[id], e);

                          //  debug(e);

                            la = str[i];

                            e = ;

                        }

                        else e++;

                    }

                    ll c1 = ,c2 = ;

                    for(int i=; i<len && str[i] == str[]; i++) c1++;

                    for(int i=len-; i>= && str[i] == str[len-];i--) c2++;

                    if(str[] == str[len-]) {

                        int id = (int)(str[] - 'a');

                        if(dp[id]) dp[id] = min(big, max(dp[id], 1ll + c1 + c2));

                    }

                    else {

                        int id = (int)(str[] - 'a');

                        if(dp[id]) dp[id] = min(big, max(dp[id], 1ll + c1));

                        id = (int) (str[len-] - 'a');

                        if(dp[id]) dp[id] = min(big, max(dp[id], 1ll + c2));

                    }

                    rep(i, , ) {

                        dp[i] = max(dp[i], tmp[i]);

                    }

                }

            }

            rep(i, , ) ans = max(ans, dp[i]);

            printf("%lld\n", ans);

            return ;

}