program main
  !
  ! Sample program of multiple IF structure
  ! Leap Year Program
  !
  implicit none
  integer :: y

  write(*,*) 'Input Year'
  read(*,*) y

  if(mod(y,4)==0) then
    if(mod(y,100)==0) then
      if(mod(y,400)==0) then
        write(*,*) 'Year',y,'is a leap year.'
      else
        write(*,*) 'Year',y,'is not a leap year.'
      end if
    else
      write(*,*) 'Year',y,'is a leap year.'
    end if
  else
    write(*,*) 'Year',y,'is not a leap year.'
  end if

end program main

実行結果