#include<bits/stdc++.h>
#define ll long long
#define pb push_back
#define mkp make_pair
#define vi vector<int>
#define SZ(x) ((int)x.size())
#define pii pair<int,int>
#define FI(n) FastIO::read(n)
#define FO(n) FastIO::write(n)
#define ull unsigned long long
#define mst(a,b) memset(a,b,sizeof(a))
#define foR(i,k,j) for(int i=(k);i>=(j);i--)
#define For(i,k,j) for(int i=(k);i<=(j);i++)
#define Foe(i,u) for(int i=lst[u],v=e[i].v;i;i=e[i].nxt,v=e[i].v)
#define IOS ios::sync_with_stdio(0),cin.tie(0),cout.tie(0)
#define Fin(s) freopen(s,"r",stdin)
#define Fout(s) freopen(s,"w",stdout)
#define file(s) Fin(s".in"),Fout(s".out")
#define INF ((1<<30)-1)
#define int long long
const int P=998244353; //
using namespace std;
template<typename T>inline void ckmax(T &a,T b) {(a<b)&&(a=b);}
template<typename T>inline void ckmin(T &a,T b) {(a>b)&&(a=b);}
inline int mul(int a,int b) {return 1ll*a*b%P;}
inline int add(int a,int b) {return a+b>=P?a+b-P:a+b;}
inline int sub(int a,int b) {return a-b>=0?a-b:a-b+P;}
inline void mulmod(int &a,int b) {a=mul(a, b);}
inline void addmod(int &a,int b) {((a+=b)>=P)&&(a-=P);}
inline void submod(int &a,int b) {((a-=b)<0)&&(a+=P);}
inline int ksm(int a,int b) {int ans=1; for(;b;b>>=1) {if(b&1) ans=1ll*ans*a%P;a=1ll*a*a%P;}return ans;}
inline void fprint(const vector<int> &f) {for(int i=0;i<(int)f.size();i++) fprintf(stderr,"%d ",f[i]); fprintf(stderr,"\n");}
inline int inv(int a) {return ksm(a,P-2);}
namespace FastIO {
	const int SIZE=1<<16; char buf[SIZE],obuf[SIZE],str[64]; int bi=SIZE,bn=SIZE,opt;
	int read(char *s) {
		while (bn) {for (;bi<bn&&buf[bi]<=' ';bi++);if (bi<bn) break; bn=fread(buf,1,SIZE,stdin),bi=0;}
		int sn=0;while (bn) {for (;bi<bn&&buf[bi]>' ';bi++) s[sn++]=buf[bi];if (bi<bn) break; bn=fread(buf,1,SIZE,stdin),bi=0;}s[sn]=0;return sn;
	}
	bool read(int& x) {if(x)x=0;int bf=0,n=read(str); if(!n) return 0; int i=0; if (str[i]=='-') bf=1,i=1; for(x=0;i<n;i++) x=x*10+str[i]-'0'; if(bf) x=-x; return 1;}
	void write(int x) {
		if(!x) obuf[opt++]='0'; else {if(x<0) obuf[opt++]='-',x=-x;int sn=0; while(x)str[sn++]=x%10+'0',x/=10;for (int i=sn-1;i>=0;i--) obuf[opt++]=str[i];}
		if (opt>=(SIZE>>1)){fwrite(obuf,1,opt,stdout); opt=0;}
	}
	void write(char x) {obuf[opt++]=x;if (opt>=(SIZE>>1)){fwrite(obuf,1,opt,stdout); opt=0;}}
	void Fflush() {if (opt) fwrite(obuf,1,opt,stdout); opt=0;}
};
inline int read() {int x; FI(x); return x;}
const int MN=5e5+5; 
int n,S,M,nowans,fans=1e18,t;
map<int,int>id; vi d; vector<pii>fr[MN];
int cnt[MN]; 
void dfs(int lst,int nmid,int ns) {
	// cerr<<d[nmid]<<' '<<ns<<' '<<lst<<endl;
	if(nmid==0) {
		int tans=nowans+max(ns,cnt[0])-min(ns,cnt[0]);
		if(tans<fans) fans=tans; 
	}
	for(auto it:fr[nmid]) {
		int x=it.first,y=it.second; 
		if(x>lst||ns<d[x]) break; 
		if(cnt[x]>0) nowans--; else nowans++; 
		cnt[x]--;  
		ns-=d[x]; 
		// if(nowans+max(ns,cnt[0])-min(ns,cnt[0])==5) {
		// 	cerr<<"? "<<d[x]<<' '<<y<<' '<<nowans<<' '<<ns<<' '<<nowans+max(ns,cnt[0])-min(ns,cnt[0])<<endl;
		// }
		dfs(x,y,ns); 
		
		if(cnt[x]<0) nowans--; else nowans++;
		cnt[x]++; 
		ns+=d[x]; 
	}
}
void works() {
	n=read(),S=read(),M=read(); 
	for(int i=1;i*i<=M;i++) {
		if(M%i==0) {
			d.pb(i); 
			if(i*i!=M) d.pb(M/i); 
		}
	}
	sort(d.begin(),d.end());
	t=SZ(d); 
	For(i,0,t-1) {
		id[d[i]]=i; 
		For(j,1,i) {
			if(d[i]%d[j]==0) {
				fr[i].pb(mkp(j,id[d[i]/d[j]])); 
			}
		}
	}
	// fprint(d); 
	For(i,1,n) {
		int x=read(); 
		if(M%x==0) cnt[id[x]]++; 
	}
	
	nowans=n-cnt[0]; 
	dfs(t-1,id[M],S);
	cout<<(fans>=1e17?-1:fans)<<endl;  
}
signed main(){
	#ifdef wasa855
		freopen("pro.in","r",stdin);
		freopen("pro.out","w",stdout);
	#endif
	int T=1;  
	while(T--) {
		works(); 
	}
	return FastIO::Fflush(),0;
}