#include<iostream> using namespace std; int main(){ int n; cin>>n; double a[n+5]; for(int i=1;i<=n;i++){ cin>>a[i]; } int max=-0x7fffffff; for(int i=1;i<n;){ for(int j=i+1;j<=n;j++){ if(a[i]+a[j]>max){ max=a[i]+a[j]; break; } } i++; } cout<<max<<endl; return 0; }