use std::collections::HashMap;


const INF: usize = 1usize << 60;

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 val2cnt = a.into_iter().map(|v| {
            let mut cnt = 1usize;
            let mut val = v;
            while val % p == 0 {
                val /= p;
                cnt += 1;
            }
            (val, cnt)
        })
        .collect::<Vec<_>>();
    let val2cnt = val2cnt.into_iter().filter(|&(v, _)| v > 1).collect::<Vec<_>>();
    if val2cnt.is_empty() {
        println!("-1");
        return;
    }
    let mut dp = vec![1usize; 100];
    dp[1] = maxval;
    for &(val, cnt) in val2cnt.iter() {
        let mut next_dp = vec![1usize; 100];
        for i in 0..100 {
            next_dp[i] = next_dp[i].max(dp[i]);
            if i >= cnt && next_dp[i-cnt] < INF {
                next_dp[i] = next_dp[i].max(next_dp[i-cnt] * val);
                if next_dp[i] > m {
                    next_dp[i] = INF;
                }
            }
        }
        dp = next_dp;
    }
    println!("{}", dp.iter().enumerate().filter(|&(_, &v)| v == INF).nth(0).unwrap().0);
}