Language: C++

                                                  #include <ext/pb_ds/assoc_container.hpp> 
                                                 #include <ext/pb_ds/tree_policy.hpp> 
                                                    #include <iostream>
                                                    #include <iomanip>
                                                    #include <sstream>
                                                    #include <cstring>
                                                    #include <vector>
                                                    #include <deque>
                                                    #include <queue>
                                                    #include <set>
                                                    #include <map>
                                                    #include <valarray>
                                                    #include <iterator>
                                                    #include <functional>
                                                    #include <limits>
                                                    #include <algorithm>
                                                    #include <numeric>
                                                    #include <cmath>
                                                    #include <cassert>
                                                    #include <unordered_map>
                                                    #include <unordered_set>
                                                    #include <stack>
                                                    using namespace std;
                                                    #define IOS ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
                                                    #define trace(x) cerr << #x << ": " << x << " " << endl;
                                                 
                                                    typedef int64_t ll;
                                                 
                                                    #define endl '\n'
                                                    #define int ll
                                                    ll mod=1e9+7;
                                                    ll mod1=1e9+6;
                                                    
                                                    ll power(ll a,ll b)
                                                    {
                                                        if(b==0) return 1;
                                                        else if(b%2==0)
                                                            return power((((a%mod)*(a%mod))%mod),b/2)%mod;
                                                        else return ((a%mod)*(power((((a%mod)*(a%mod))%mod),b/2)%mod))%mod;
                                                    }
                                                   
                                                   using namespace __gnu_pbds;
                                                    #define ordered_set tree<pair<int,int>, null_type,less<pair<int,int>>, rb_tree_tag,tree_order_statistics_node_update>
                                                    //find_by_order(k)  returns iterator to kth element starting from 0;
                                                    //order_of_key(k) returns count of elements strictly smaller than k;
                                                    //erase,insert same as normal set
                                                
                                                int32_t main()
                                                {
                                                    IOS
                                               

                                                    
                                                    int n,m,x,y;
                                                    cin>>n>>m>>x>>y;
                                                    int a[n+1];
                                                    vector<pair<int,int>> v;
                                                     map<int,int> m1;
                                                     set<int> s;
                                                    for(int i=1;i<=n;++i)
                                                    {
                                                        cin>>a[i];
                                                        v.push_back({a[i],i});
                                                        m1[a[i]]++;
                                                        s.insert(a[i]);
                                                

                                                    }
                                                    sort(v.begin(),v.end());
                                        

                                                    int q=v[n-y].first;
                                                    cout<<q<<endl;
                                                    int ans=0;
                                                    int prev=0; 
                                                    for(auto i:s)
                                                    {                                                    
                                                        //cout<<i<<" "<<m1[i]<<" ";
                                                        if(i>=q)
                                                        {
                                                            ans+=m1[i];
                                                            continue;
                                                        }
                                                        if(i+m>=q)
                                                        {

                                                            if(prev+m1[i]-1>=x-1)
                                                                ans+=m1[i];
                                                        }
                                                        prev+=m1[i];
                                                        //cout<<ans<<"A"<<endl;
                                                    }
                                                    int prev=0;
                                                    for(auto i:s)
                                                    {
                                                        if(i+m<q)
                                                        {
                                                            prev+=m1[i];
                                                            continue;
                                                        }
                                                        if(prev+m1[i]-1>=x-1)
                                                        {
                                                            prev+=m1[i];
                                                            continue;
                                                        }
                                                    }

                                                    cout<<ans;


 
                                                 }    

Compiler output:
a.cc: In function 'int32_t main()':
a.cc:93:57: error: redeclaration of 'll prev'
   93 |                                                     int prev=0;
      |                                                         ^~~~
a.cc:75:57: note: 'll prev' previously declared here
   75 |                                                     int prev=0;
      |                                                         ^~~~