#include<fstream.h>
ifstream f("date.in");

long cmmdc(long a, long b)
{ while(a!=b)
   if(a>b) a=a-b;
   else b=b-a;
  return a;
}

void main()
{ int n,l,i,max=0;
  long x,y;
  f>>n>>x;
  l=1;
  for(i=2;i<=n;i++)
  { f>>y;
	if(cmmdc(x,y)==1) l++;
	else if(max<l) { max=l;
					 l=1;
				   }
	x=y;
  }
  cout<<max;
}