#include<cstdio>
#include<vector>
#include<cstring>
#include<iostream>
#include<algorithm>
#include<cmath>
const int N = 110000;
const int mod = 998244353;
const int lgM = 25;
using ll = long long;
const ll INF = 0x3f3f3f3f3f3f3f3f;
ll read(){
    ll x=0,flag=1;char c;
    while((c=getchar())<'0' || c>'9') if(c=='-') flag=-1;
    while(c>='0' && c<='9') x=(x<<3)+(x<<1)+(c^48),c=getchar();
    return x*flag;
}
ll divor[N],a[N];int dcnt[N],sufd[N];
const int BB = 201;
const int BM = 2550;
ll dp[BB*lgM][BM];
std::pair<int,int> lst[BB*lgM][BM];
std::vector<std::pair<int,int> > nxtD[BM];
int trs[BM][BM];
ll ans=INF;int cd=0;ll S,M;
inline ll myabs(ll a) {return a<0?-a:a;}
void dfs(int i, int jj, int curcnt, ll curS, ll curM, ll curans){
    if (curS>S || curM<M&&(1.0*curM*divor[jj]>M+1e-6) ) return;
    if (i==cd||curM==M)
    {
        if (curM!=M) return;
        curans += myabs((S-curS) - dcnt[1]);
        ans=std::min(ans,curans);
        return;
    }
    ll D=divor[jj];
    // if (curM==M)
    // {
    //     curans += myabs((S-curS) - dcnt[1]);
    //     if (ans==-1) ans=curans;
    //     else ans=std::min(ans, curans);
    //     return;
    // }
    if (curS+D>S&&curM!=M) return;
    for (auto &[to, j] : nxtD[i])
    {
        if (j<jj) break;
        int nxtcnt = (j==jj?curcnt:0) + 1;
        dfs(to, j, nxtcnt, curS+divor[j], divor[to], curans + (nxtcnt<=dcnt[j]?-1:1));
    }
}
void print_ans(ll S,ll M)
{
    if (M==1) return;
    print_ans(lst[S][M].first, lst[S][M].second);
    printf("%lld ", S - lst[S][M].first);
}
int main()
{
    int n=read(),m=0;S=read();M=read();
    ll extra=0;
    //dcnt[1]=100000;
    for (int i=1;i<=n;++i)
    {
        ll x=read();
        if (M%x || x>S) ++extra;
        else a[++m]=x;
    }
    double t=clock();
    ll SN = sqrt(M);
    for (ll i=1;i<=SN;++i)
        if (M%i==0)
        {
            divor[++cd]=i;
            if (i*i!=M) divor[++cd]=M/i;
        }
    std::sort(divor+1,divor+1+cd);
    //for (int i=1;i<=cd;++i) printf("%lld ",divor[i]);
    std::sort(a+1,a+1+m);
    for (int i=1,R=1;i<=cd;++i)
        while(R<=m&&a[R]==divor[i])
            ++dcnt[i], ++R;
    for (int i=cd;i;--i) sufd[i]=sufd[i+1]+dcnt[i];
    memset(dp,0x3f,sizeof(dp));
    int mxp=1;
    int B=M<=BB-1?(int)M:BB-1;
    for (int i=1;i<=cd;++i)
        for (int j=cd;j>1;--j)
        {
            ll D = divor[i]*divor[j];
            int idx = std::lower_bound(divor+1,divor+1+cd,D) - divor;
            if (idx<=cd&&divor[idx]==D&&D/divor[i]==divor[j]) 
            {
                trs[i][j]=idx;
                nxtD[i].emplace_back(idx, j);
            }else trs[i][j]=-1;
        }
    dfs(1, 0, 0, 0, 1, sufd[2]);
    if (ans!=INF) ans+=extra;
    printf("%lld\n",ans==INF?-1:ans);
    return 0;

    std::cerr<<"cd = "<< cd <<'\n';
    std::cerr<<"binary search takes " << (clock()-t)/CLOCKS_PER_SEC << "seconds\n";
    t = clock();
    dp[0][1]=sufd[2];
    //printf("sufd[2]=%lld\n",sufd[2]);
    for (int i=2,z=i&1;i<=cd&&divor[i]<=B;++i,z^=1)
    {
        ll D=divor[i];
        mxp=i;
        for (int s=B*lgM-1;s>=0;--s)
            for(int id=cd;id;--id)
            {
                ll now=dp[s][id];
                if (now==INF) continue;
                int curid=id;
                for (int j=0;curid>0;++j,curid=trs[curid][i])
                {
                    // if (now + (j<=dcnt[i]?-j:j-dcnt[i]) < dp[s+j*D][curid])
                    //     lst[s+j*D][curid] = std::make_pair(s, id);
                    dp[s+j*D][curid] = std::min(dp[s+j*D][curid], now + (j<=dcnt[i]?-j:j-dcnt[i]));
                    // if (s+j*D<=77) 
                    //     printf("dp[%d][%lld]=%lld\n",s+j*D,divor[curid], dp[s+j*D][curid] );
                }
            }
    }
    std::cerr<<"DP takes " << (clock()-t)/CLOCKS_PER_SEC << "seconds\n";
    t = clock();
    int z=mxp&1;
    // print_ans(77, cd);printf("\n");
    for (int s=0;s<=B*lgM-1;++s)
        for (int id=1;id<=cd;++id)
        {
            ll now=dp[s][id];
            if (now==INF) continue;
            //if (id==cd) printf("dp[%d][%lld]=%lld\n",s,divor[id], now);
            dfs(id, mxp+1, 0, s, divor[id], now);
        }
    if (ans!=INF) ans+=extra;
    std::cerr<< "DFS Search time " << (clock()-t)/CLOCKS_PER_SEC << '\n';
    printf("%lld\n",ans==INF?-1:ans);
    return 0;
}