use std::io::{Read, stdin};
use std::collections::HashMap;

fn main() {
    let mut buf = String::new();
    stdin().read_to_string(&mut buf).unwrap();
    let mut tok = buf.split_whitespace();
    let mut get = || tok.next().unwrap();
    macro_rules! get {
        ($t:ty) => (get().parse::<$t>().unwrap());
        () => (get!(i64));
    }
    
    let n = get!();
    let mut map = HashMap::new();
    for _ in 0..n {
        let s = get!(String);
        let &c = map.get(&s).unwrap_or(&0);
        map.insert(s, c+1);
    }
    
    let mut freq = 0;
    let mut ans = 0;
    
    for (s, &c) in map.iter() {
        if c > freq {
            freq = c;
            ans = s.len();
        } else if c == freq && s.len() > ans {
            ans = s.len();
        }
    }
    ans -= 2;
    println!("{}", ans);
}