прошу помочь в чем проблема?Solution was not declared in this scope Solution ob;,

// { Driver Code Starts
//Initial function template for C++

#include<bits/stdc++.h>
using namespace std;

 // } Driver Code Ends

int kthSmallest(int arr[], int l, int r, int k)
    {
        int p;
        int t;
            for(int i = 0; i < r - 1; i++)
            {
              for(int j = 0; j < r - 2 ; j++)
              {
                if(arr[j] < arr[j+1])
                {
                  t = arr[j];
                  arr[j] = arr[j + 1];
                  arr[j + 1] = t;
                }
              }
            }
            p =  arr[k];
            cout << p;
    }

// { Driver Code Starts.
 
int main()
{
    int test_case;
    cin>>test_case;
    while(test_case--)
    {
        int number_of_elements;
        cin>>number_of_elements;
        int a[number_of_elements];
        
        for(int i=0;i<number_of_elements;i++)
            cin>>a[i];
            
        int k;
        cin>>k;
        Solution ob;
        cout<<ob.kthSmallest(a, 0, number_of_elements-1, k)<<endl;
    }
    return 0;
}  // } Driver Code Ends