Help me in solving GDSUB problem

help
,
1

My issue

My code

#include <bits/stdc++.h>
using namespace std;
#define ll long long
int main() {
	// your code goes here
	ll n,k;
	cin>>n>>k;
	ll m=1e9+7;
	ll arr[n];
	set<ll> s;
	unordered_map<ll,ll> co;
	for(int i=0;i<n;i++){
	    cin>>arr[i];
	    co[arr[i]]++;
	    s.insert(arr[i]);
	}
	if(s.size()<k) k=s.size();
	return 0;
}

Problem Link: CodeChef: Practical coding for everyone