#include <iostream>
#include <cstdio>
#include <vector>
#include <algorithm>
#include <utility>
#include <string>

using namespace std;

const int INF = 1e9;


int main() {
	int n;

	cin >> n;
	string str(1000001, '.');
	int x;
	for (int i = 0; i < n; i++) {
		cin >> x;
		str[x] = 'x';
	}
	// cout << str.substr(1, 30) << endl;

	int ans = INF;
	int pos1 = str.find('x', 0);
	int pos2 = str.find('x', pos1 + 1);
	while (pos2 != string::npos) {
		ans = min(ans, pos2 - pos1);
		pos1 = pos2;
		pos2 = str.find('x', pos2 + 1);
	}

	if (ans == INF) {
		ans = 0;
	}
	cout << ans << endl;
	return 0;
}