#include <iostream>
#include <vector>

#define SZ 1000000

using namespace std;

bool X[SZ + 1];

int main()
{
	int i, N, x, d = SZ + 1;
	cin >> N;

	for (i = 0; i < N; i++)
		X[cin >> x, x] = true;

	vector<int> p;
	for (i = 0; i <= SZ; i++) 
		if(X[i]) p.push_back(i);

	if (p.size() <= 1) {
		cout << 0 << endl;
		return 0;
	}
	for (i = 0; i < p.size() - 1; i++)
		if (d > p[i + 1] - p[i]) d = p[i + 1] - p[i];

	cout << d << endl;
	return 0;
}