use std::io::prelude::*;
use std::io::stdin;
use std::fmt::Debug;
use std::str;

#[derive(Debug, Clone)]
struct List {
    pub prev: Option<usize>,
    pub next: Option<usize>,
    pub used: bool,
}

fn main() {
    let mut list: Vec<List> = vec![List { prev: None, next: None, used: false }; 26];
    let n: usize = {
        let mut s = String::new();
        stdin().read_line(&mut s).unwrap();
        s.trim().parse().unwrap()
    };
    if n == 1 {
        let mut s = String::new();
        stdin().read_line(&mut s).unwrap();
        println!("{}", s.trim());
        return;
    }
    for i in 0..n {
        let mut s = String::new();
        stdin().read_line(&mut s).unwrap();

        if s.trim().len() == 1 {
            let i = (s.as_bytes()[0] - 'A' as u8) as usize;
            list[i].used = true;
        }
        for b in s.trim().as_bytes().windows(2) {
            let i = (b[0] - 'A' as u8) as usize;
            let j = (b[1] - 'A' as u8) as usize;
            list[i].next = Some(j);
            list[j].prev = Some(i);
            list[i].used = true;
            list[j].used = true;
        }
    }
    let n: usize = {
        let mut s = String::new();
        stdin().read_line(&mut s).unwrap();
        s.trim().parse().unwrap()
    };
    if n == 1 {
        let mut s = String::new();
        stdin().read_line(&mut s).unwrap();
        println!("{}", s.trim());
        return;
    }
    for i in 0..n {
        let mut s = String::new();
        stdin().read_line(&mut s).unwrap();

        if s.trim().len() == 1 {
            let i = (s.as_bytes()[0] - 'A' as u8) as usize;
            list[i].used = true;
        }
        for b in s.trim().as_bytes().windows(2) {
            let i = (b[0] - 'A' as u8) as usize;
            let j = (b[1] - 'A' as u8) as usize;
            list[i].next = Some(j);
            list[j].prev = Some(i);
            list[i].used = true;
            list[j].used = true;
        }
    }
    let mut cursor = None;
    let mut s = vec![];
    let mut count = 0;
    for (i,c) in list.iter().enumerate() {
        if c.prev.is_none() && c.next.is_some() {
            if cursor.is_some() {
                println!("-1");
                return;
            }
            cursor = c.next.clone();
            s.push(i as u8 + 'A' as u8);
        }
        if c.used {
            count += 1;
            //println!("{}: {:?}", (i as u8 + 'A' as u8) as char, c);
        }
    }
    if cursor.is_none() {
        println!("-1");
        return;
    } else {
        while cursor.is_some() {
            let n = *cursor.as_ref().unwrap();
            s.push(n as u8 + 'A' as u8);
            cursor = list[n].next;
        }
    }
    if s.len() != count {
        println!("-1");
    } else {
        println!("{}", str::from_utf8(&s).unwrap());
    }
}