#include <cstdio>
#include <iostream>

using namespace std;

const int MaxN = 1005;

int n, num[ MaxN ], br, M;

int main( void ) {
    scanf( "%d", &n );
    for( int i = 0; i < n; ++i )
        scanf( "%d", &num[ i ] );

    for( int i = 0; i < n; ++i ) {
        br = num[ i ];
        while( 1 ) {
            if( i+1 < n ) {
                if( num[ i ] < num[ i+1 ] )
                    ++i; else break;
            } else break;
        }
        M = max( M, num[ i ]-br );
    }
    printf( "%d\n", M );
    return 0;
}