1.2.0.0/22 is divided into 1.2.0.0/23 and 1.2.2.0/23 And further 1.2.0.0/23 divided into 1.2.0.0/24 and 1.2.1.0/24,
And 1.2.2.0/23 is divided into 1.2.2.0/24 and 1.2.3.0/24
we get four networks by VLSM
and supernet is mask is 1.2.0.0/22 or mask=255.255.252.0