Hi I would like some help on this visual force page
what I need is to have a page that displays all contacts and their account next to each other.
with checkbox next to them to select them and add them as target (custom object) which has a trigger when contact is created a target is created with basic info. 
the controller is 

public class ContactsController {

    public String selectedContactsIds { get; set; }

    public PageReference addContact() {
        return null;
    }


    public List contacts {get; set;}
    Map contactMap {get; set;}
     public string selectedContactIds {get; set;}
    string parentContactId;
    public ContactsController() // CHANGE THIS (SelectConcorrenteController TO ConcorrenteController)
    {
        parentContactId = ApexPages.currentPage().getParameters().get('accId');
        contactMap = new Map([select Id, Name from Contact]);
        contacts = contactMap.Values();
    }
    
     public PageReference addTargets() {
        List contactIds = selectedContactIds.split(',');
        List Targets = new List();
        
        for (string s : contactIds)
        {
            Target__c Target = new Target__c(Target__c = parentContactId, Name = contactMap.get(s).Name); 
            Targets.add(target);
        }
        if (Targets.size() > 0)
        {
            insert Targets;
        }
        string strPageRef = '"javascript:window.close();"';
        return new PageReference(strPageRef);
    }
}

Visual force is

When i added  it gives me the error 

SObject row was retrieved via SOQL without querying the requested field: Contact.Account 
 

When I added to Account.Name

contactMap = new Map([select Id, Name, Account.Name from Contact])
I received this error 
Expression value does not resolve to a field
Error is in expression '{!con.Account}' in component in page contactsvf

If anyone would know how to fix this??