#include <bits/stdc++.h>
#define ll long long
#define pb push_back
using namespace std;
void Flash(){
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
}
ll cnt[1000000],dp[1000000],a[1000000];
ll n,m,k,x,y,z;
ll maxi=-1e9,mini=1e9,maxi1=-1e9,mini1=1e9,cnt1,cnt2,cnt3,ans,i;
int main(){
    Flash();
    cin>>n;
    for(int i=1; i<=n; i++){
        cin>>a[i];
        cnt[a[i]]++;
    }
    for(int i=1; i<=100000; i++){
        dp[i]=max(dp[i-1],dp[i-2]+i*cnt[i]);
    }
    cout<<dp[100000];
}

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