#include <iostream>
#include <cstdio>
#include <cmath>
#include <cstdlib>

using namespace std;

int maks=0;
int niz[1020];
int N;
int sad;
int cnt=1;

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

    for ( int i = 0 ; i < N ; ++i ){
        cnt = 1;
        while (niz[i+cnt-1] < niz[i+cnt]){
            sad = niz[i+cnt] - niz[i] ;
            if (sad > maks) maks = sad ;
            cnt++;
        }
    }
printf("%d",maks);

return 0;
}