#pragma GCC optimize("Ofast")
#pragma GCC target("avx2")

char*mmap();
#define RD(v) int v=0;{int _c;while(_c=*rp++-48,_c>=0)v=v*10+_c;}

int d[300001];

main(){
	char*rp=mmap(0l,1l<<28,1,2,0,0ll);
	while(*rp++>=48);
	int z=0;
	do{
		RD(a);
		if(d[a]<0) continue;
		int l=d[a]+1;d[a]=-1;
		z=z>l?z:l;
		for(int p=a;p+=a,p<=300000;){
			d[p]=d[p]>l?d[p]:l;;
		}
	}while(*rp);
	{
		long n=0,d=0;
		while(++n,d=d<<8|0x30|z%10,z/=10);
		write(1,&d,n);
	}
	_exit(0);
}