#include <iostream>
#include <algorithm>
using namespace std;
 
int main(){
	int N;
	cin >> N;
	int X[N];
	for(int i = 0; i < N; i++){
		cin >> X[i];
	}
	sort(X, X + N);
	int ans = 0;
	int back = X[0];
	for(int i = 1; i < N; i++){
		if((X[i] - back < ans || ans == 0) && back != X[i]){
			ans = X[i] - back;
		}
		back = X[i];
	}
	cout << ans << endl;
}