#include <bits/stdc++.h>
using namespace std;
int n;
int cnt[100005];
long long dp[100005][2];

main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);
    freopen("TEST.inp", "r", stdin);
    freopen("TEST.out", "w", stdout);
    cin >> n;
    for (int i = 1; i <= n; i++) {
        int a;
        cin >> a;
        cnt[a]++;
    }

    int _n = 1e5;
    for (int i = 1; i <= _n; i++) {
        dp[i][0] = max(dp[i - 1][0], dp[i - 1][1]);
        dp[i][1] = dp[i - 1][0] + 1LL * cnt[i] * i;
    }

    cout << max(dp[_n][0], dp[_n][1]) << '\n';

    return 0;
}