Bulk IP address and Subnet mask to CIDR conversion

I have a task to convert a whole heap of IP address to their CIDR notation and would like to do this in Excel

I have
Column A = IP Address
Column B = Subnet Mask
ie
10.227.68.2 255.255.255.0
10.227.69.2 255.255.254.0
10.227.80.192 255.255.255.128


On another worksheet i have a table with the subnet and CIDR so i can do a VLOOKUP
ie
....
255.255.252.0 /22
255.255.254.0 /23
255.255.255.0 /24
255.255.255.128 /25
255.255.255.192 /26
....

Would like a formula that can then take that information and create the full CIDR notation in column C
Network ID/CIDR

From the above example the output should be:
10.227.68.2 255.255.255.0 10.227.68.0/24
10.227.71.2 255.255.254.0 10.227.70.0/23
10.227.80.192 255.255.255.128 10.227.80.128/25

I have failed multiple times in creating this and there is a lot of forums asking for the opposite CIDR to subnet mask