noname60

#include<bits/stdc++.h>
using namespace std;


typedef long long ll;


ll _min = (ll)1e9, x, res = -(ll)1e18;


ll Read() { ll x; cin >> x; return x; }
ll maximize (ll &u, ll v) { return u = max(u, v); }
ll minimize (ll &u, ll v) { return u = min(u, v); }


int main(){
    for (ll n = Read(); n--;) {
        cin >> x;
        maximize(res, x - _min);
        minimize(_min, x);
    }
    cout << res;
}