#include<bits/stdc++.h>
using namespace std;

int main(){
    int N,in;
    vector<int> x;

    cin >> N;
    while(cin >> in) x.push_back(in);
    sort(x.begin(),x.end());

    int ans=numeric_limits<int>::max();
    for(int i=0;i<x.size()-1;i++){
        if(ans>(x[i+1]-x[i]) && (x[i+1]-x[i])!=0) ans=x[i+1]-x[i];
    }
    if(ans!=numeric_limits<int>::max()) cout << ans << endl;
    else cout << 0 << endl;

    return 0;
}