// yukicoder 135 (http://yukicoder.me/problems/135)
#include<cstdio>
#include<algorithm>
#include<vector>
#define rep(i,a) for(int i=0;i<(a);++i)
#define all(a) (a).begin(), (a).end()

const int MAX_N = 100000;

int N;
std::vector<int> xs;

int main()
{
	scanf( "%d", &N );
	rep( i, N )
	{
		int X;
		scanf( "%d", &X );
		xs.push_back(X);
	}

	std::sort( all(xs) );
	xs.erase( std::unique( all(xs) ), xs.end() );

	int ans = 1<<30;
	rep( i, xs.size()-1 )
		ans = std::min( ans, abs(xs[i+1]-xs[i]) );

	printf( "%d\n", ans==1<<30?0:ans );

	return 0;
}