use std::collections::BTreeSet;

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 maxval = *a.iter().max().unwrap();
    if maxval > m {
        println!("1");
        return;
    }
    let a = a.into_iter().map(|v| {
            let mut ret = v;
            let mut cnt = 1usize;
            while ret % p == 0 {
                ret /= p;
                cnt += 1;
            }
            (ret, cnt)
        })
        .filter(|&(val, cnt)| val > 1)
        .collect::<BTreeSet<_>>()
        .into_iter()
        .collect::<Vec<_>>();
    if a.is_empty() {
        println!("-1");
        return;
    }
    let INF = m + 1;
    let mut dp = vec![0usize; 900];
    dp[1] = maxval;
    for i in 0..a.len() {
        let mut next_dp = vec![0usize; 900];
        let (val, cnt) = a[i];
        for j in 0..900 {
            next_dp[j] = next_dp[j].max(dp[j]).min(INF);
            if j + cnt < 900 {
                next_dp[j+cnt] = next_dp[j+cnt].max(next_dp[j] * val).min(INF);
            }
        }
        dp = next_dp;
    }
    println!("{}", (0..900).filter(|&v| dp[v] == INF).nth(0).map(|v| v as isize).unwrap_or(-1));
}