#include <iostream>
using namespace std;
int N,A;
int Mx,Mn,ans;
int main() {
ios::sync_with_stdio(0);
cin.tie(0);
cin >> N;
cin >> A;
Mx = A;
Mn = A;
ans = Mx - Mn;
for(int x=1; x<N; x++) {
cin >> A;
if (Mx < A) {
Mn = A;
Mx = A;
}
if(Mx > A) {
Mn = A;
if(ans < Mx - Mn) ans = Mx - Mn;
}
}
if(ans <= 0) cout << 0;
else cout << ans;
}