func_code_string: #include <bits/stdc++.h>   using namespace std;   const int N = 1e5 + 5;   long long DP[N];   int n;   int a[N];   int freq[N];   long long solve(int num) {     if (num < 1) return 0;     if (DP[num] != -1) return DP[num];     return DP[num] =                max((long long)num * freq[num] + solve(num - 2), solve(num - 1));   }   int main() {     memset(DP, -1, sizeof DP);     scanf( %d , &n);     int mx = 0;     for (int i = 0; i < n; ++i) {       scanf( %d , a + i);       ++freq[a[i]];       if (a[i] > mx) mx = a[i];     }     printf( %lld n , solve(mx));   }   