#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define lll __int128
#define eb emplace_back
const int N=3e3+5;
const ll INF=1e18;
int n,tp;ll m,c,s,ans=INF,d[N];
vector<int> vc[N];
unordered_map<ll,ll> cnt,dp[N];
bool chk(ll x) {return (lll)x*x*x<=m;}
int id(ll x) {return lower_bound(d+1,d+tp+1,x)-d;}
void W(int x,ll y,ll w)
{
    if(y>c) return;
    if(!dp[x].count(y)) dp[x][y]=w;
    else dp[x][y]=min(dp[x][y],w);
}
int main()
{
    scanf("%d %lld %lld",&n,&c,&m);
    for(int i=1;i<=n;++i) {ll x;scanf("%lld",&x);++cnt[x];}
    for(int i=1;1ll*i*i<=m;++i) if(!(m%i))
    {
        d[++tp]=i;
        if(1ll*i*i<m) d[++tp]=m/i;
    }
    dp[1][0]=0;
    sort(d+1,d+tp+1);
    for(int i=tp,x;i;--i)
        if(d[i]>1 && chk(d[i]))
        {
            x=cnt[d[i]];
            for(int j=tp;j;--j)
            {
                ll t1=m/d[j];
                for(auto &[k,w]:dp[j])
                {
                    ll t=1;
                    for(int l=1;;++l)
                    {
                        t=1ll*t*d[i];
                        if(t1%t) break;
                        W(id(d[j]*t),k+l*d[i],w+abs(x-l));
                    }
                    w+=x;
                }
            }
        }
    for(auto [x,w]:cnt) if(x>1 && (m%x || !chk(x))) s+=w;
    int x=cnt[1];
    for(int i=1;i<=tp;++i) for(int j=1;j<i;++j)
        if(!(d[i]%d[j]) && !chk(d[j]) && !chk(d[i]/d[j])) vc[i].eb(d[j]);
    for(int i=1;i<=tp;++i)
    {
        for(auto [j,w]:dp[i])
        {
            ll t=m/d[i];
            if(d[i]==m && j<=c) ans=min(ans,w+s+abs(c-j-x));
            if(chk(t)) continue;
            if(j+t<=c) ans=min(ans,w+s+abs(c-j-t-x)+(cnt[t]?-1:1));
            for(auto k:vc[id(t)])
            {
                ll l=t/k;
                if(j+k+l>c) continue;
                if(k==l) ans=min(ans,w+s+abs(c-j-k-l-x)-cnt[k]+abs(cnt[k]-2));
                else ans=min(ans,w+s+abs(c-j-k-l-x)+(cnt[k]?-1:1)+(cnt[l]?-1:1));
            }
        }
    }
    printf("%lld\n",ans<INF?ans:-1);return 0;
}