WRITE A JCL TO FORMAT THE FILE SO THAN ALL THE CHILD UNDER ONE PARENT IS IN ONE RECORD
input
PARENT | CHILD
A123456789|B123456789
C123456789|D123456789
A123456789|E123456789
F123456789|G123456789
G123456789|H123456789
I123456789|J123456789
F123456789|H123456789
output
A123456789|B123456789,E123456789
C123456789|D123456789
F123456789|G123456789,H123456789
G123456789|H123456789
I123456789|J123456789