#include <bits/stdc++.h>
#define MOD 1000000007

using namespace std;

typedef pair<int,int> P;
typedef pair<int,pair<int,int>> PP;
typedef long long LL;

const double EPS = 1e-8;
const int INF = 1e9;

int dy[] = {0,1,0,-1};
int dx[] = {1,0,-1,0};

int main(void) {
	int N;
	int ret = INF;
	cin >> N;
	vector<int> x(N);
	for(int i=0;i<N;i++){
		cin >> x[i];
	}
	for(int i=0;i<N;i++){
		for(int j=i+1;j<N;j++){
			if(x[i] == x[j])continue;
			ret = min(ret,abs(x[i]-x[j]));
		}
	}
	if(ret == INF)cout << 0 << endl;
	else cout << ret << endl;
}