public class AccountswithReplatedContacts {
    public list<Account>acc{get;set;}
    public String Accountname{get;set;}
    public String Response {get;set;}
    Public JSONwrapper wrapper{get;set;}
    
    public AccountswithReplatedContacts(){
        
        //getresposnsefromCallout();
    }
    
    public void getresposnsefromCallout(){
        //String search=''+Accountname+'';
       // system.debug('searchstring'+search);
String Endpoint='https://'+URL.getSalesforceBaseUrl().getHost()+'/services/data/v39.0/query/?q=SELECT +Id,Name ,(Select +id,name +from+contacts)+FROM + Account + where + name=\''+String.escapeSingleQuotes(Accountname)+'\'';
         System.debug('Endpoint'+Endpoint);
         HttpRequest req = new HttpRequest();
        req.setMethod('GET');
        string autho = 'Bearer '+userInfo.getSessionId();
        req.setHeader('Authorization', autho);
        req.setEndpoint(Endpoint);
         Http http = new Http();
        HTTPresponse res= http.send(req);
        response = res.getBody();
        system.debug('response'+response);
       wrapper= (JSONwrapper) System.JSON.deserialize(response, JSONwrapper.class);
        system.debug('wrapper'+wrapper);
        //wrapper = (JSONwrapper) JSON.deserializeStrict(response, JSONwrapper.class);
                }
 
    }

------------------
Wrapper class
---------------------------
public  class Jsonwrapper
{    
    public Integer totalSize;
    public boolean done;
    List<AccountWrapper> accWrapper = new List<AccountWrapper>();
    public Jsonwrapper(integer p_tot,boolean p_done,List<Account> p_rec)
    {
         totalSize=p_tot;
         done=p_done;
		 for(Account acc : p_rec)
		 {
			AccountWrapper aw = new aw(acc.Name);
			List<ContactWrapper> conWrapper = new List<Contact>();
			for(Contact con : acc.Contacts)
			{
				ContactWrapper cw = new ContactWrapper(con.totalSize, con.done, con.records);
				conWrapper.add(cw);
			}
			aw.conList.addAll(conWrapper);
		 }
			accWrapper.addAll(aw);
		 }

	
	public class AccountWrapper
	{
		Public String name{get;set;}
		public List<ContactWrapper> conList{get;set;}
		
		public AccountWrapper(String n)
		{
			name = n;
			conList = new List<ContactWrapper>();
		}
	}

public class ContactWrapper
{
    public Integer totalSize;
    public boolean done;
    public contact record;
    
    public ContactWrapper(integer p_tot,boolean p_done,Contact p_rec)
    {
        totalSize=p_tot;
        done=p_done;
        records=p_rec;
    }
}
}