#include <bits/stdc++.h>
using namespace std;

int main()
{
    int n;
    cin >> n;
    map<string, int> m;
    for (int i = 0; i < n; i++)
    {
        string s;
        cin >> s;
        m[s]++;
    }
    int ans = 0, num = -1;
    for (auto &p : m)
    {
        if (num <= p.second)
        {
            num = p.second;
            ans = p.first.size() - 2;
        }
    }
    cout << ans << endl;
    return 0;
}