#include<......>
#define int long long
#define fo(i,a,b) for(int i=a;i<=b;i++)
using namespace std;
int n,ans;
int a[100001],f[100001];
main(){
	cin>>n;
	fo(i,1,n){
		cin>>a[i];
		int v=0;
		fo(j,1,n){
			if(a[i]>a[j]){
				v=max(v,f[j]);
			}
		}
		f[i]=a[i]+v;
		ans=max(ans,f[i]);
	}
	cout<<ans;
	return 0;
}