/*
  LANG: C++
  ID: Matteo Kinkela
  PROG: Uspon
*/
#include <algorithm>

#include <cstdio>
#include <cstring>
#include <cctype>
#include <climits>
#include <cmath>

#include <vector>
#include <set>
#include <queue>
#include <stack>
#include <list>
#include <map>
#include <bitset>

#include <utility>
#include <valarray>

#include <string>
#include <iostream>

using namespace std;

int N;
int Arr;
int Last;
int Max = -1, Min = 10000;
int Sol;

int main() {
    scanf( "%d", &N );
    for( int i = 0 ; i < N ; ++i ) {
         scanf( "%d", &Arr );
         if( Arr > Last ) {
             Last = Arr;
             Min = min( Min, Arr );
             Max = max( Max, Arr );
             Sol = max( abs( Max - Min ), Sol );
             //printf( "PROBA: %d %d\n", Min, Max );
         }
         else {
              Sol = max( abs( Max - Min ), Sol );
              Last = Arr;
              Min = Arr;
              Max = Arr;
              //printf( "" )
         }
    }
    printf( "%d\n", Sol );
return 0;
}