#include<bits/stdc++.h>
#define fri(i,n) for(int i=0;i<n;i++)
#define fr(i,a,b) for(int i=a;i<=b;i++)
#define ol(v) v.begin(),v.end()
#define forc(v) for(auto it:v)
#define se second
#define fi first
#define pb push_back
#define pf push_front
#define MX 1e18
#define MN -MX
using namespace std;
typedef long long ll;
typedef long double ld;
template <typename T> istream&operator>>(istream &inp, vector<T> &vec){
fri(i,vec.size()) inp>>vec[i];
return inp;
}
template <typename T> ostream&operator<<(ostream &oup, vector<T> vec){
forc(vec) oup<<it<<" ";
oup<<"\n";
return oup;
}
int arr[100005];
int main(){
ios::sync_with_stdio(false);
#ifdef DBG
freopen("in", "r", stdin);
#endif
int mx = -1;
fill(arr, arr+100005, 0);
int n;
cin>>n;
fri(i,n){int k; cin>>k; arr[k]++; mx = max(mx, k);}
//arr[2] = 2*arr[2];
for(int i = 2;i<=mx; i++) arr[i] = max(i*arr[i]+arr[i-2], arr[i-1]);
cout<<arr[mx]<<"\n";
return 0;
}
//
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