#include<iostream>
#include<algorithm>
#include<cmath>

using namespace std;

const int N = 1010;

int n;
int a[N];
int main()
{
    cin>>n;
    for(int i = 0; i<n; i++) cin>>a[i];
    sort(a,a+n);
    int ans = 100010;
    for(int i = 1; i+1<n; i++)
    {
        ans = min(ans,a[i]-a[i-1]);
        ans = min(ans,a[i+1]-a[i]);
    }
    cout<<ans;
    return 0;
}