title: Code to be run on multiple specific sheets
body: <p>I want to run a code on multiple sheets. The sheet names are: Sheet1, Sheet2, 1, 2 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 and Summary. I define my sheets of interest= (1, 2, 3, 4 and Summary). The code should run only on these sheets. If any sheet in sheets of interest is not present, it should run for all other sheet of interest, i.e. if 1,2 are not present it should run for 3,4 and Summary.</p>