// Problem: P4447 [AHOI2018初中组] 分组
// Memory Limit: 128 MB
// Time Limit: 1000 ms

// Author: Milonia     (O v O)

#include <iostream>
#include <algorithm>
using namespace std;

#define int long long
#define int_INF 0x3f3f3f3f

int n;
const int N=1e5+10;
int a[N];

signed main(){
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	
	cin>>n;
	for (int i=0;i<n;i++) cin>>a[i];
	sort(a,a+n);
	// for (int i=0;i<n;i++) cout<<a[i]<<' ';
	
	int ans=int_INF,res=-2e9,j=int_INF;
	for (int i=0;i<n;i++) {
		if (res==-2e9 || res+1!=a[i]) {
			res=a[i];
			ans=min(ans,j);
			// cout<<j<<endl;
			j=1;
		} else if (res+1==a[i]) j++,res++;
 	}
 	ans=min(ans,j);
 	cout<<ans<<endl;
	
	return 0;
}