Module ComplexType
  Implicit None
  Type ComplexNumber
    Real :: realnum, imagenum
  End Type ComplexNumber
  
  Interface Assignment(=)
    Module Procedure ComplexAssign
  End Interface

Contains

  Subroutine ComplexAssign(z,realvalue)
    Type(ComplexNumber), Intent(INOUT) :: z
    Real, Intent(IN) :: realvalue
    z%realnum = realvalue
    z%imagenum = realvalue
  End Subroutine ComplexAssign

End Module ComplexType

Program Main
  Use ComplexType
  Implicit None
  Type(ComplexNumber) :: z
  Real :: a
  
  Print *, " Type a real value a : "
  Read *, a
  z = a
  Print *, " a + ai = ", z

End Program Main