trigger newacconsal on Contact (after insert) {
    set<Id> ids=new set<Id>()
    
    map<id,Account> macc=new map<id,Account>();
    map<id,Contact> mcon=new map<id,Contact>();
    
        map<id,Account> macc=trigger.old;

}


Error

Illegal assignment from Map<Id,Contact> to Map<Id,Account>