iMac retrieve old linux partition after dual boot removal

On my iMac I installed a dual boot with Linux Mint. However, I realized that the videos were freezing some times, so I deleted the Linux partition. Now, the Mac is working normally, but instead of having a partition of 1 TB, I just have a 800GB's total space on my Hard Disk. How can I do to retrieve the 200GB of space that were on the Linux partition I deleted? Below is the output from diskutil list. /dev/disk0 #: TYPE NAME SIZE IDENTIFIER #: TYPE NAME SIZE IDENTIFIER 0: GUID_partition_scheme *1.0 TB disk0 1: EFI EFI 209.7 MB disk0s1 2: Apple_HFS Macintosh HD 800.0 GB disk0s2 3: Apple_HFS Recovery HD 650.0 MB disk0s3 4: FFFFFFFF-FFFF-FFFF-FFFF-FFFFFFFFFFFF 1.0 MB disk0s4