task 3( ds lab 3) 3rd sem

#include<bits/stdc++.h>
using namespace std;
int main()
{
    int n,i,sum=0,j;
    cin>>n;
    int arr[2*n];
    for(i=0;i<2*n;i++)
    {
        cin>>arr[i];
    }
    sort(arr,arr+i);
    for(j=0;j<i;j=j+2)
        sum=sum+arr[j];
    cout<<sum;
}