program hanoimain
! recursive towers of hanoi program in 
! fortran 90
    integer n
    n = 5
    call hanoi(n,'a','c','b')
end
!
recursive subroutine hanoi(n,frompeg,auxpeg,topeg)
    integer n
    character*1 frompeg,auxpeg,topeg
    if (n == 1) then
        write(6,*)"Move disk 1 from peg ", frompeg, " to peg ", topeg
    else
        call hanoi(n-1,frompeg,auxpeg,topeg)
        write(6,101) n, frompeg,topeg
        101 FORMAT(1x,"Move disk ",i1," from peg ", A1, " to peg ", A1)
        call hanoi(n-1,auxpeg,topeg,frompeg)
    endif
end