#include <cstdlib>
#include <iostream>

using namespace std;

int main()
{
    int n, v, pv=1001, tu=0, nvu=0;
    cin >> n;
    for ( int i = 0; i < n; ++i )
    {
        cin >> v;
        if ( v <= pv )
        {
            if ( nvu < tu )
                nvu = tu;
            tu = 0;
        }
        else if ( i == n-1 && pv < v )
        {
            tu += v-pv;
            if ( nvu < tu )
                nvu = tu;
        }
        else
            tu += v-pv;
        pv = v;
    }
    cout << nvu << endl;
}