merge bfiles with different allele format by plink

Hello,

I want to merge two bfiles using plink. However, one bfile is written as below.

1 rs123 0 123 A G

1 rs234 0 234 G T

The other file is as below.

1 rs123 0 123 1 2

1 rs234 0 234 1 2

All SNPs are like this, so I cannot remove those SNPs to merge. Any ideas would be appreciated. Thank you!