insert into long datatype

[msuresh]

There are 2 tables for example
a(a number,b long raw) and b(a number,b long raw)

i used a command to insert all the rows from b into a and i have some errors.Let me know how to resolve this.
insert into a select * from b;
*
ERROR at line 1:
ORA-00997: illegal use of LONG datatype