Error: Compile Error: Invalid constructor syntax, name=value pairs can only be used for SObjects in line Contact con =new Contact ( ... please 
 Lead ld=new Lead(
        FirstName='Cal',
        LastName='Smith',
        Company='IBM'
      );
    Contact con = new Contact(
        FirstName='Paul',
        LastName='Smith'
    
   );

Challenge Not yet complete... here's what's wrong:  There was an unexpected error while verifying this challenge. Usually this is due to some pre-existing configuration or code in the challenge Org. We recommend using a new Developer Edition (DE) to check this challenge. If you're using a new DE and seeing this error, please post to the developer forums and reference error id: EPCRKTQS

Challenge Not yet complete... here's what's wrong:  There was an unexpected error while verifying this challenge. Usually this is due to some pre-existing configuration or code in the challenge Org. We recommend using a new Developer Edition (DE) to check this challenge. If you're using a new DE and seeing this error, please post to the developer forums and reference error id: EPCRKTQS