Find the bug

Q: locate the error in this GAMS code:

  19   
  20   
  21    Sets
  22         i   canning, plants   / seattle, san-diego /
  23         j   markets          / new-york, chicago, topeka / ;
  24   
  25    Parameters
  26   
  27         a(i)  capacity of plant i in cases
  28           /    seattle     350
****                      $361
**** 361  Values for domain 1 are unknown - no checking possible
  29                san-diego   600  /
  30   
  31         b(j)  demand at market j in cases
  32           /    new-york    325
  33                chicago     300
  34                topeka      275  / ;