#include <bits/stdc++.h>
#define PB push_back
#define MP make_pair
#define REP(i,n) for (int i=0;i<(n);i++)
#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define ALL(a) (a).begin(),(a).end()
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> P;
const int INF=1e9;
int main(){
      int n;
      cin>>n;
      vector<int> x(n);
      REP(i,n)cin>>x[i];
      sort(ALL(x));
      x.erase(unique(ALL(x)),x.end());
      int ans=INF;
      REP(i,x.size())if(i!=0)ans=min(ans,x[i]-x[i-1]);
      if(ans!=INF)cout<<ans<<endl;
      else cout<<0<<endl;
}