use std::io::{self, BufRead};
use std::collections::HashMap;


fn main() {
    let stdin = io::stdin();

    let lines = stdin.lock().lines()
        .filter_map(|x| x.ok())
        .collect::<Vec<_>>();

    let mut count: Vec<HashMap<char, u16>> = vec![HashMap::new(); 1024];

    for line in lines {
        for (i, ch) in line.chars().enumerate() {
            *count[i].entry(ch).or_insert(0) += 1;
        }
    }

    let corrected_most: String = count.iter()
        .filter_map(|x| {
            let mut vec: Vec<_> = x.iter().collect();

            vec.sort_by_key(|k| k.1);

            vec.pop()
        })
        .map(|x| *x.0)
        .collect();

    let corrected_least: String = count.iter()
        .filter_map(|x| {
            let mut vec: Vec<_> = x.iter().collect();

            vec.sort_by_key(|k| k.1);
            vec.reverse();

            vec.pop()
        })
        .map(|x| *x.0)
        .collect();

    println!("corrected_most={}", corrected_most);
    println!("corrected_least={}", corrected_least);
}