#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef string str;
int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    ll n;
    cin >> n;
    ll a[n], nmin = LONG_MAX;
    for (ll i = 0; i < n; i++) cin >> a[i];
    sort(a, a + n);
    for (ll i = 1; i < n; i++)
    {
        if (a[i-1] == a[i] && a[i-1] != 0) nmin = min(nmin, 1LL);
        else if (a[i-1] != 0 && a[i] != 0) nmin = min(nmin, abs(a[i-1] - a[i]));
    }
    if (nmin != LONG_MAX) cout << nmin;
    else cout << 0;
    return 0;
}