#include<bits/stdc++.h>
using namespace std;
long long n,a[5001],b[5001][3],sum;
int main()
{
	cin>>n;
	cin>>a[1];
	for(long long i=2;i<=n;++i)
	{
		cin>>a[i];
		if(sum==0)
		{
			sum++;
			b[sum][1]=a[i]-1;
			b[sum][2]=a[i];
			continue;
		}
		long long ans=0,tmp;
		for(long long j=1;j<=sum;++j)
		{
			if((a[i]-1)%b[j][1]==0)
			{
				ans=1;
				tmp=j;
				break;
			}
		}
		if(ans==0)
		{
			sum++;
			b[sum][1]=a[i]-1;
			b[sum][2]=a[i];
			continue;
		}
		if(a[i]-b[tmp][2]>b[tmp][1])
		{
			sum++;
			b[sum][1]=a[i]-1;
			b[sum][2]=a[i];
			continue;
		}
		b[tmp][2]=a[i];
	}
	cout<<sum<<endl;
	return 0;
}