/*

     DP：从1到最大值，dp[i][1/0] 选或不选，递推更新最大值

 */

 #include <cstdio>

 #include <algorithm>

 #include <cmath>

 #include <cstring>

 using namespace std;

 typedef long long ll;

 const int MAXN = 1e5 + ;

 const int INF = 0x3f3f3f3f;

 ll dp[MAXN][];

 ll cnt[MAXN];

 ll work(int mx)

 {

     ll ret = ;

     for (int i=; i<=mx; ++i)

     {

         dp[i][] = dp[i-][] + cnt[i] * i;

         dp[i][] = max (dp[i-][], dp[i-][]);

         ret = max (ret, dp[i][]);

         ret = max (ret, dp[i][]);

     }

     return ret;

 }

 int main(void)      //Codeforces Round #260 (Div. 1) A. Boredom

 {

     int n;    scanf ("%d", &n);

     int mx = ;

     for (int i=; i<=n; ++i)

     {

         int x;  scanf ("%d", &x);    cnt[x]++;

         mx = max (mx, x);

     }

     printf ("%I64d\n", work (mx));

     return ;

 }