#include<iostream>
#include<cmath>
#include<cstring>
#include<algorithm>
#include<ctime>
using namespace std;
int a[100001];
bool cmp(int a,int b)
{
	return a<b;
}
int main()
{
	long long n,minn=1000000001,sum=0;
	cin>>n;
	for(int i=1;i<=n;i++)
	{
		cin>>a[i];
	}
	sort(a+1,a+1+n,cmp);
	for(int i=1;i<=n;i++)
	{
		if(a[i-1]+1!=a[i]&&i!=1)    
		{
			if(sum<=minn)    minn=sum;
			sum=0;
		}
		else
		{
			sum++;
		}
	}
	cout<<minn;
	return 0;
}