use std::collections::HashMap;

const INF: usize = 1usize << 60;

fn gcd(a: usize, b: usize) -> usize {
    if b == 0 { return a; }
    gcd(b, a%b)
}

fn main() {
    let mut nmp = String::new();
    std::io::stdin().read_line(&mut nmp).ok();
    let nmp: Vec<usize> = nmp.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();
    let n = nmp[0];
    let m = nmp[1];
    let p = nmp[2];
    let mut a = String::new();
    std::io::stdin().read_line(&mut a).ok();
    let a: Vec<usize> = a.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();

    let a = a.into_iter().filter(|&v| v % p > 0 && v > 1).collect::<Vec<_>>();
    if p == 1 || a.is_empty() {
        println!("-1");
        return;
    }
    let mut dp = HashMap::new();
    dp.insert(1usize, 0usize);
    for &v in a.iter() {
        let mut next_dp = HashMap::new();
        for (&val, &cnt) in dp.iter() {
            next_dp.insert(val, cnt);
            for i in 1.. {
                let value = v.pow(i);
                let lgcdval = gcd(value, p);
                let rgcdval = gcd(val, p);
                if lgcdval == p || rgcdval == p || gcd(lgcdval*rgcdval, p) == p {
                    break;
                }
                let target = if value >= m || value * val >= m {
                        m
                    } else {
                        value * val
                    };
                let minval = (*next_dp.get(&target).unwrap_or(&INF)).min(i as usize + cnt);
                next_dp.insert(target, minval);
                if target == m {
                    break;
                }
            }
        }
        dp = next_dp;
    }
    if dp.contains_key(&m) {
        println!("{}", dp.get(&m).unwrap());
    } else {
        println!("-1");
    }
}