GATE CSE 2022 Q63: Disk accesses to insert a block mid-file: contiguous vs linked

Consider two files systems $A$ and $B$, that use contiguous allocation and linked allocation, respectively. A file of size 100 blocks is already stored in A and also in B. Now, consider inserting a new block in the middle of the file (between 50th and 51st block), whose data is already available in the memory. Assume that there are enough free blocks at the end of the file and that the file control blocks are already in memory. Let the number of disk accesses required to insert a block in the middle of the file in $A$ and $B$ are $n_A$ and $n_B$, respectively, then the value of $n_A + n_B$ is_________.