#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int main() {
	int N;
	cin >> N;
	vector<int> X(N, 0);
	vector<int> balance(N-1,0);
	for (int i = 0; i < N;i++) {
		cin >> X[i];
	}
	sort(X.begin(), X.end());
	for (int i = 1; i < N;i++) {
		if (X[i] == X[i - 1]) { balance[i - 1] = 9999999; }
		else {
			balance[i - 1] = X[i] - X[i - 1];
		}
	}
	sort(balance.begin(), balance.end());
	if (balance[0] == 9999999) {
		cout << 0 << endl;
	}
	else
	{
		cout << balance[0] << endl;
	}
	return 0;
}