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


int main() {
    int num;
    
    std:cin >> num;
    
    int n;
    vector<int> numbers;
    for(int i=0;i<num;i++)
    {
       std::cin >> n;
       numbers.push_back(n);
    }
    std::sort(numbers.begin(), numbers.end());
    int diff= abs(numbers[1]-numbers[2]);
    for(int i=0;i<numbers.size()-1;i++)
    {
       int d=abs(numbers[i+1]-numbers[i+2]);    
       if(d<diff) diff=d;
    }
    std::cout << diff;
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    return 0;
}