#include<bits/stdc++.h>
using namespace std;

#define cout cerr
#define rep(i,a,b) for(int i=(a);i<=(b);++i)
#define per(i,a,b) for(int i=(a);i>=(b);--i)

typedef long long ll;
typedef pair<int,int> pii;
#define FR first
#define SE second

inline void rd(int &x){
	x=0;char ch=getchar();int f=1;
	while(ch<'0'||ch>'9'){
		if(ch=='-')f=-1;
		ch=getchar();
	}
	while(ch>='0'&&ch<='9'){
		x=x*10+ch-'0';
		ch=getchar();
	}
	x*=f;
}
inline void rd(ll &x){
	x=0;char ch=getchar();int f=1;
	while(ch<'0'||ch>'9'){
		if(ch=='-')f=-1;
		ch=getchar();
	}
	while(ch>='0'&&ch<='9'){
		x=x*10+ch-'0';
		ch=getchar();
	}
	x*=f;
}

typedef pair<ll,ll> P;
typedef vector<P> H;
#define rez resize
int n;ll l;
#define Maxn 300010
ll a[Maxn];

ll gcd(ll a,ll b){
	if(!b)return a;
	return gcd(b,a%b);
}

H add(H ans,P cur){
	int t=ans.size()-1;
	if(ans[t].SE+cur.SE<=ans[t].FR){
	//	cout<<"enter "<<endl;
		ll tmp=gcd(ans[t].SE,cur.SE);
	//	cout<<"tmp "<<tmp<<" "<<cur.FR<<" "<<ans[t-1].FR<<" "<<ans[t-1].SE<<endl;
		ans.pop_back();ans=add(ans,P(cur.FR,tmp));
		return ans;
	}
	if(ans[t].SE>=cur.SE){
		ll len=ans[t].FR-ans[t-1].FR;
	//	cout<<"len "<<len<<endl;
		len%=cur.SE;ans.pop_back();
	//	cout<<"len "<<len<<endl;
		if(len)ans=add(ans,P(ans[t-1].FR+len,len));
		ans=add(ans,P(cur.FR,cur.SE));
		return ans;
	}else{
		ll at=ans[t].FR-cur.SE;
	//	cout<<"at "<<at<<" "<<cur.FR<<" "<<cur.SE<<" "<<ans[t].FR<<" "<<ans[t].SE<<endl;
		if(at<0){
			ans.push_back(cur);return ans;
		}
		bool fl=false;
		if(at==0)fl=true;
		else{
		per(i,t,1)
			if(at>ans[i-1].FR){
				if((at-ans[i-1].FR)%ans[i].SE==0){
					fl=true;
					break;
				}
			//		cout<<"fuck i "<<i<<" "<<ans[i].FR<<" "<<ans[i].SE<<endl;
				H res;res.rez(i);rep(j,0,i-1)res[j]=ans[j];
				ll hh=ans[i].SE;
				if(at-ans[i-1].FR>hh)res=add(res,P((at-ans[i-1].FR)/hh*hh+ans[i-1].FR,hh));
				res=add(res,P(at,(at-ans[i-1].FR)%hh));
				res=add(res,P((at-ans[i-1].FR)/hh*hh+ans[i-1].FR+hh,hh-(at-ans[i-1].FR)%hh));
				if(at+hh<ans[i].FR)res=add(res,P(ans[i].FR,hh));
				rep(j,i+1,t)res=add(res,ans[j]);
				res=add(res,cur);
				return res;
			}
		}
		if(fl){
			if(cur.SE%ans[t].SE==0)cur.SE=ans[t].SE;
			ans.push_back(cur);
			return ans;
		}
	}
}

int main(){
	while(true){
		rd(n);rd(l);
		if(n==0&&l==0)break;
		rep(i,1,n)rd(a[i]);a[++n]=1;
		sort(a+1,a+n+1);n=unique(a+1,a+n+1)-a-1;
		H ans;
		ans.rez(2);ans[0]=P(0,0);ans[1]=P(1,1);
		rep(i,2,n){
			ans=add(ans,P(a[i],a[i]-a[i-1]));
	//		cout<<i<<" "<<a[i]<<" "<<ans.size()<<" ----------"<<endl;
	//		for(int j=1;j<ans.size();++j)cout<<ans[j].FR<<" "<<ans[j].SE<<endl;
		}
		ll Ans=0;
		for(int i=1;i<ans.size();++i)Ans+=(ans[i].FR-ans[i-1].FR)/ans[i].SE;
		printf("%lld\n",Ans);
	}
	return 0;
}/*
4 12
7 1 3 9
*/