#include<iostream>
#include<cmath>
#include<algorithm>
using namespace std;
typedef long long LL;
const int N = 1e5 + 10;
int a[N];
int n, mmin = 1, jishu = 1, zhenmin = 0x3f3f3f3f;
int main()
{
	cin >> n;
	for (int i = 1; i <= n; ++i)cin >> a[i];
	sort(a + 1, a + 1 + n);
	while (jishu <= n - 1)
	{
		while ((a[jishu] + 1) == a[jishu + 1]&&a[jishu]!= a[jishu + 1])
		{
			++mmin;
			++jishu;
		}
		zhenmin = min(mmin, zhenmin);
		++jishu;
		mmin = 1;
	}
	cout << zhenmin;
	return 0;
}