#include <cstdio>
#include <algorithm>

using namespace std;

int n, v[1010], sol, sool;

int main( void ) {

	scanf( "%d", &n );
	for( int i = 0; i < n; ++i )
		scanf( "%d", &v[i] );

	for( int i = 1; i < n; ++i ) {
		if( v[i] > v[i-1] ) {
			sol += v[i] - v[i-1];
			sool = max( sol, sool );
		} else sol = 0;
	}

	printf( "%d\n", sool );

    return 0;
}