Program 7 : a4r4a, strgr4a, r4astrg, r4aa4

      program prog7
      implicit none

      character a*21 /'This is a test string'/,b*21
      integer frmtr4a(6),frmta4(6)

      print *,'Here is the initial string:',a
      call strgr4a(a,frmtr4a,1,21)
      call r4aa4(frmtr4a,frmta4,21)
      call a4r4a(frmtr4a,frmta4,21)
      call r4astrg(b,frmtr4a,1,21)
      print *,'Changing 4 times of format gives:',b
            
      stop
      end