func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     long long int n;     cin >> n;     long long int a[n], mx = 0;     for (int i = 0; i < n; i++) {       cin >> a[i];       if (a[i] > mx) mx = a[i];     }     long long int freq[mx + 1];     for (int i = 0; i < mx + 1; i++) {       freq[i] = 0;     }     for (int i = 0; i < n; i++) {       freq[a[i]]++;     }     long long int dp[mx + 1];     dp[0] = 0;     dp[1] = freq[1];     for (int i = 2; i <= mx; i++) {       dp[i] = max(dp[i - 1], (freq[i] * i) + dp[i - 2]);     }     cout << dp[mx];   }   