#include <cstdio>
#include <iostream>

using namespace std;

int main()
{
    int n,i,j,polje[1001],max,poc;
    cin >> n;
    max=0;
    for (i=1;i<=1000;++i) polje[i]=0;
    for (i=1;i<=n;++i) cin >> polje[i];
    i=1;
    while (i<n)
    {
        j=i+1;
        while (polje[j]>polje[j-1] && j<=n) ++j;
        if (polje[j-1]-polje[i]>max) max=polje[j-1]-polje[i];
        i=j;
    }
    cout << max << endl;
    return 0;
}