/*
ZCO 2014 Smart Phone
Yash Mathur
*/
#include <iostream>
#include <algorithm>
using namespace std;
int main() {
int n;
cin>>n;
long long a[n], max=0, test;
for(int i=0;i<n;++i){
cin>>a[i];
}
sort(a, a+n);
for(int i=0;i<n;++i){
test = a[i]*(n-i);
if(test>max)
max=test;
}
cout<<max;
return 0;
}
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