#include <iostream>
using namespace std;




int main(){
	int n;
	cin>>n;
	int x[n];
	int absv = 1000000;
	int abt;

	for (int i = 0; i < n ; ++i)
	{
		cin>>x[i];
	}

	for (int i = 0; i < n - 1; ++i)
	{
		for (int j = i+1; j < n; ++j)
		{
			if(x[i] == x[j]){
				cout<<"0"<<endl;
				return 0;
			}
			if(x[i] > x[j]){
				abt = x[i] - x[j];
			}else{
				abt = x[j] - x[i];
			}

			if( abt <= absv ){
				absv = abt;
			}
		}
	}

		cout<<absv<<endl;

}