C++ :

#include<iostream>
#include<queue>
#include<vector>
#include<algorithm>
using  namespace  std;
const int N=30010;
int  n,m; 
int a[N],b[N];
int  main()
{
    cin>>n>>m;
    for(int i=0;i<n;i++)cin>>a[i];
    for(int j=0;j<m;j++)cin>>b[j];
    sort(b,b+m);
    priority_queue<int> left;
    priority_queue<int,vector<int>,greater<int>> right;
    
    int i=0,j=0;  
    while(i<n || j<m)  
    {
      while(j<m && b[j]==i)
        {
           cout<<right.top()<<endl;
           left.push(right.top());
           right.pop();
           j++;
            
        }
        int x=a[i];
        if(left.empty()||x>=right.top()) right.push(x);
        else
        {
            left.push(x);
            right.push(left.top());
            left.pop();
        }
        i++;
    }
    return 0;
}