#include <iostream>
#include <algorithm>
using namespace std;
int main()
{
    int n; cin>>n;
    vector<int> a(n);
    for(int& v: a) cin>>v;
    sort(begin(a), end(a));
    a.erase(unique(begin(a), end(a)), end(a));

    if (a.size()==1)
        cout<<0<<endl;
    else {
        int res=a[1]-a[0];
        for(int i=2;i<a.size();++i) res=min(res, a[i]-a[i-1]);
        cout<<res<<endl;
    }
}