#include <iostream>
#include <algorithm>
using namespace std;
const int N = 1e6+10;
int a[N],dp[N];
int main() {
int n;
cin >> n;
for (int i = 1; i <= n; i++){
cin>>a[i];
}
int minn=1e9;
for(int i=1;i<=n;i++){
if(a[i]<=minn){
minn=a[i];
dp[i]=dp[i-1];
}else{
dp[i]=max(a[i]-minn,dp[i-1]);
}
}
cout<<dp[n];
return 0;
}