#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;


int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    int n;
    cin>>n;
    int a[n];
    for(int i=0;i<n;i++)
        {
        cin>>a[i];
    }
    int d=0;
    int n1=n;
    for(int i=0;i<n;i++)
        {
        n1=n1-1;
        d=d+n1;
    }
 
    int f[d];
    int s=0;
    for(int i=0;i<n;i++)
        {
        for(int j=i+1;j<n;j++)
            {
            if(s<=d)
            {
                f[s]=abs(a[i]-a[j]);
        
                s++;
            }
        }
    }
    int temp;
      for(int i=0;i<n;i++){
        for(int j=i;j<n;j++){
            if(f[i] > f[j])
            {
                temp = f[i];
                f[i] = f[j];
                f[j] = temp;
               
            }
        }
      }
    
        cout<<f[0];
   
    return 0;
}