#include<iostream>
#include<algorithm>
#include <vector>
#include<cmath>
#include<iomanip>
using namespace std;
typedef long long int lont;
int main() {
	int N;
	cin >> N;
	if (N == 1) {
		cout << 0 << endl;
	}
	else {
		vector<int>veca(N);
		for (int ia = 0; ia < N; ia++) {
			cin >> veca.at(ia);
		}
		sort(veca.begin(), veca.end());
		vector<int>vecb(N - 1);
		for (int ib = 0; ib < N - 1; ib++) {
			vecb.at(ib) = veca.at(ib + 1) - veca.at(ib);
		}
		sort(vecb.begin(), vecb.end());
		int cnt = 0;
		for (int ic = 0; ic < N - 1; ic++) {
			if (vecb.at(ic) != 0) {
				cout << vecb.at(ic) << endl;
				cnt++;
				break;
			}
		}
		if (cnt == 0) {
			cout << 0 << endl;
		}
	}
}