#include<bits/stdc++.h>

using namespace std;

#define ll long long
#define mp make_pair
#define pb push_back
#define pf push_front
#define int long long

signed main()
{
    ios_base::sync_with_stdio(false);
    //freopen("fight.in", "r", stdin);
    //freopen("fight.out", "w", stdout);

    int n;
    cin >> n;
    int a[n];
    for (int i = 0; i < n; i++)
    {
        string s;
        cin >> s;
        a[i] = (int)s.size();
    }

    int dp[2][n];
    for (int i = 0; i < 2; i++)
    {
        for (int j = 0; j < n; j++)
        {
            dp[i][j] = (int)1e9;
        }
    }

    dp[0][0] = a[0];
    dp[1][0] = 0;

    for (int i = 1; i < n; i++)
    {
        dp[1][i] = min(dp[0][i - 1], dp[1][i]);
        dp[0][i] = min(dp[0][i], max(min(dp[0][i - 1], dp[1][i - 1]), a[i]));
    }

    cout << min(dp[0][n - 1], dp[1][n - 1]);

    return 0;
}