#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
using namespace std;
int main()
{
    int size, num;
    vector<int> arr;
    vector<int> digit;
    int temp = 0, count = 0;
    cin >> size;
    while (temp < size)
    {
        cin >> num;
        arr.push_back(num);
        temp++;
    }
    for (int i = 0; i < arr.size(); i++)
    {
        if (arr[i] > 9)
        {
            while (arr[i] > 0)
            {
                digit.push_back(arr[i]%10);
                arr[i] = arr[i] / 10;
                count++;
            }
        }
        else {
            digit.push_back(arr[i]);
            count++;
        }
    }
    sort(digit.begin(),digit.end(),greater<int>());
    double final=0;
    int numb=digit.size();
    for(int i=0;i<digit.size();i++)
    {
        final+=(digit[i]*pow(10,numb-1));
        numb--;
    }
    cout<<final;

}

Line 19: error: iostream: No such file or directory
Line 17: error: vector: No such file or directory
Line 20: error: algorithm: No such file or directory
Line 16: error: cmath: No such file or directory
Line 5: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'namespace'
In function 'main':
Line 9: error: 'vector' undeclared (first use in this function)
Line 9: error: (Each undeclared identifier is reported only once
Line 9: error: for each function it appears in.)
Line 9: error: expected expression before 'int'
Line 10: error: expected expression before 'int'
Line 12: error: 'cin' undeclared (first use in this function)
Line 16: error: 'arr' undeclared (first use in this function)
Line 19: error: 'for' loop initial declaration used outside C99 mode
Line 25: error: 'digit' undeclared (first use in this function)
Line 35: error: 'greater' undeclared (first use in this function)
Line 35: error: expected expression before 'int'
Line 38: error: redefinition of 'i'
Line 19: error: previous definition of 'i' was here
Line 38: error: 'for' loop initial declaration used outside C99 mode
Line 40: warning: incompatible implicit declaration of built-in function 'pow'
Line 43: error: 'cout' undeclared (first use in this function)