Iterating Group standard object records in salesforce

[KRISH9]

The following in the SOQL query for Users

List<User> u = [SELECT Id FROM User];

Am able to get the id to iterate. Now i would like to get the id of Group standard object

List<Group> g = [SELECT Id FROM Group];

List<EntitySubscription>   es1 = [select Id from  EntitySubscription where SubscriberId =: j and ParentId NOT IN :usr ]; 

am retriving all entity subscriptions whose subscriber id not in the list of users. It is working fine. Now i want to retrive the entity subscriptions whose subscriber id not in the group also. For that i am writing the query like as above 

List<EntitySubscription>   es1 = [select Id from  EntitySubscription where SubscriberId =: j and ParentId NOT IN :grp ]; 

Am getting the following error. 

Error: AutoDeleteSubscriptions2 Compile Error: Invalid bind expression type of SOBJECT:Group does not match domain of foreign key

Please any one can help me on this how to retrive the entity subscriptions whose subscriber id not in the group.

[Moti]

Can you post the whole code block ?

[KRISH9]

public class AutoDeleteSubscriptions2
{
public List<User> usr ;
public List<EntitySubscription> es ;
public Map<String,ID> m1 = new Map<String,ID>();
public Map<String,ID> m2 = new Map<String,ID>();
public List<EntitySubscription> lest;
public List<EntitySubscription> es1;
public List<EntitySubscription> es2;
public List<Group> grp ;
public void deleteSubscriptions()
{
usr = [SELECT Id FROM User];
es = [SELECT Id,SubscriberId FROM EntitySubscription];

grp = [SELECT Id FROM Group];

System.debug('************GRoup****************'+grp);

System.debug(' Entity Subscription size : '+es.size()+' User Size : '+ usr.size());

for(User u : usr)
{
m1.put(u.Id,u.Id);
}
System.debug('***********User Ids**********'+m1.values()+'*****Map Size****'+m1.size());

System.debug(' Entity Subscription size : '+es.size());

for (EntitySubscription e : es)
{
m2.put(e.SubscriberId,e.SubscriberId);
}

System.debug('*************Entity Subscription User Ids***********'+m2.values()+'*****Map Size****'+m2.size());
// Comparing two map values
Set<String> ls = m1.keySet();

Set<String> ls1 = m2.keySet();
System.debug('**************List Elements*****************'+ls.size()+'*************'+ls1.size());

for (Id i :ls)
{
for ( Id j : ls1)
{
System.debug(' I = '+i +' J = '+j);
if ( i == j)
{
System.debug(' Both are equal ' + i +'***************** '+ j);
List<EntitySubscription> es = [select Id from EntitySubscription where SubscriberId =: j];
System.debug('**************************List Size ***********************'+es.size());

if(es.size() > 20)
{
es1 = [select Id from EntitySubscription where SubscriberId =: j and ParentId NOT IN :usr order by CreatedDate limit 5];
delete es1;
}
}
}
}
}
}

In query now i added the user lisr like NOT IN : usr the same way want to check with the group.

[KRISH9]

In the query now i want to retrive all the EntitySubscriptions except the users and group remaining i want to retrive for that am trying put both the lists.

NOT IN : usr  and NOT IN : grp

for group am getting error please help me out on this.