#include <iostream>
    #include <bits/stdc++.h>
    typedef long long ll;
    using namespace std;
    ll n,k;
    vector <ll> v;
    vector <pair <ll,ll> > ar;
    ll dp[100005];
    ll solve(ll i,ll elements){
        ll temp1,temp2,temp3,c1 = 0,c2 = 0, found = 0;
        if(elements== 0) return 0;
        if(i>=ar.size()) return -1e17;
        if(dp[i] +1) return dp[i];
        if(i!=0 ) {temp1 = ar[i-1].second; if(ar[i].first-ar[i-1].first==1){elements-=temp1;ar[i-1].second= 0;}}
        if(i!=ar.size()-1){temp2=ar[i+1].second;if(ar[i+1].first-ar[i].first==1){elements-=temp2;ar[i+1].second = 0; found = 1;}}
        temp3 = ar[i].second;
        ar[i].second = 0;
        if(found){
        c1 = solve(i+2,elements-temp3)+ar[i].first*temp3;
        } else {
        c1 = solve(i+1,elements-temp3)+ar[i].first*temp3;
        }
        ar[i].second = temp3;
        if(i!=0) { if(ar[i].first-ar[i-1].first==1){elements+=temp1;ar[i-1].second= temp1;}}
        if(i!=ar.size()-1){if(ar[i+1].first-ar[i].first==1){elements+=temp2;ar[i+1].second = temp2;}}
        c2 = solve(i+1,elements);
        return dp[i] = max(c1,c2);
    }

    int main()
    {
        cin>>n;
        for(int i = 0;i<n;i++){
            cin>>k;
            v.push_back(k);
        }
        sort(v.begin(),v.end());
        ar.push_back(make_pair(v[0],1));
        ll temp = 0;
        for (int i = 1;i<n;i++) {
            if(v[i] != ar[temp].first) {
                temp++;
                ar.push_back(make_pair(v[i],1));
            } else {
                ar[temp].second++;
            }
        }
        memset(dp,-1,sizeof dp);
        if(ar.size()==1){cout<<ar[0].first*ar[0].second;}
        else cout<<solve(0,n);
        return 0;
    }