#include <cstdio>
#include <algorithm>

using namespace std;

int niz[ 1005 ];

int main( void )
{
	int n;
	scanf( "%d", &n );
	
	for( int i = 0; i < n; ++i )
		scanf( "%d", &niz[ i ] );
	
	int sol = 0;
	for( int i = 0; i < n; ++i )
	{
		int st = niz[ i ]; int j = i + 1;
		while( j < n && niz[ j ] > niz[ j - 1 ] )
			++j;	
		sol = max( sol, niz[ j - 1 ] - niz[ i ] );
	}
	
	printf( "%d\n", sol );
	
	return 0;	
}