#include <iostream>
#include <cstdlib>
#include <algorithm>

using namespace std;
int n,i,u[1010],d[1010],c;

int main ()
{
    
    cin>>n;
    for (i=0;i<n;i++) cin>>u[i];
    for (i=0;i<n;i++)
    {
        if (u[i]<u[i+1]) d[c]=d[c]+u[i+1]-u[i];
        else  c++;       
    }
    sort(d,d+n);
    cout<<d[n-1];
//system("PAUSE");
return 0;
}