c       Here we demonstrate the "if - then - else if" construction.
c       The last "else if" has been replaced with "else". This allows
c       you to cover all remaining cases without listing them.
        program sign
        real x
        print *, "What is your number ?"
        read *, x
        if (x .gt. 0) then
                print *, "Your number is positive."
        else if (x .lt. 0) then
                print *, "Your number is negative."
        else 
                print *, "Your number is neither positive nor negative."
        end if
        print *, "Bye"
        end