//# pragma GCC optimize(2)
#include <bits/stdc++.h>
//#define int long long
#define SZ(x) (int)(x).size()
#define fs first
#define sc second
#define PII pair<int,int>
#define ls(u) (u)<<1
#define rs(u) (u)<<1|1
#define pb push_back
#define eb emplace_back
#define vi vector<int>
#define vvi vector<vi >
#define vI vector<PII>
#define db double
#define all(a) (a).begin(),(a).end()
#define die cout << "???" << endl
//#define endl '\n'
using namespace std;
const int mod = 998244353;
//const int mod = 1169996969;
//const int mod = 1e9+7;
//const int inf = LLONG_MAX;
const int inf = 0x3f3f3f3f;
//const int inf = 1e9;
//const db PI = acos(-1.0);
const db eps = 1e-5;
typedef long long ll;
typedef unsigned long long  ull;
const int N = 1e5+5,M = 3e5+5,K = 30;

inline int rd() {
    int f = 0; int x = 0; char ch = getchar();
    for (; !isdigit(ch); ch = getchar()) f |= (ch == '-');
    for (; isdigit(ch); ch = getchar()) x = (x << 1) + (x << 3) + ch - '0';
    if (f) x = -x;
    return x;
}

void write(int a) {if(a>=10)write(a/10);putchar(a%10+'0');}
void wt(int a) {if(a < 0) {putchar('-');a = -a;}write(a);}
void wwt(int a){wt(a);putchar('\n');}

void write(ll a) {if(a>=10)write(a/10);putchar(a%10+'0');}
void wt(ll a) {if(a < 0) {putchar('-');a = -a;}write(a);}
void wwt(ll a){wt(a);putchar('\n');}

int lowbit(int x) {return (x&(-x));}
int n,m,k;

bool cmp(string a,string b)
{
    return SZ(a) < SZ(b);
}

int cnt[N];

signed main()
{
    ios::sync_with_stdio(0);
    cin.tie(0),cout.tie(0);
    #ifndef ONLINE_JUDGE
    freopen("in.txt", "r+", stdin);
    freopen("out.txt", "w+", stdout);
    #endif
    cin >> n;
    
    vector<string> v(n);

    for(int i = 0;i<n;i++)
    {
        cin >> v[i];
    }

    sort(all(v),cmp);

    for(int i = 0;i<n;i++)
    {
        int len = SZ(v[i]);
        cnt[len]++;
    }

    int id = 1;

    while(cnt[id]) id++;

    map<string,int> mp;

    int ans = 0;

    for(int i = 0;i<n;i++)
    {
        if(SZ(v[i]) > id) break;

        if(SZ(v[i]) == 1)
        {
            mp[v[i]] = 1;
            ans = 1;
            continue;
        }

        string l = "",r = "";

        for(int j = 0;j<SZ(v[i]);j++)
        {
            if(j == 0)
            {
                l += v[i][j];
            }

            else if(j == SZ(v[i]) - 1)
            {
                r += v[i][j];
            }

            else 
            {
                l += v[i][j];
                r += v[i][j];
            }
        }

        if(mp.count(l) && mp.count(r))
        {
            mp[v[i]] = 1;
            ans = SZ(v[i]);
        }
    }

    cout << ans;

    return 0;

}