PROGRAM VECTS
*
* Calculates the vector  a*x + y, where a is a real constant and
* x and y are  given vectors.
*
      INTEGER N
      PARAMETER(N=6)
      REAL A(100), B(100), C
      OPEN(UNIT=1,FILE='inp.dat',STATUS='UNKNOWN')
      DO 10 I = 1,N
        A(I) = 0.
        B(I) = 0.
 10   CONTINUE
      DO 20 I = 1,N
        READ(1,*) A(I), B(I)
 20   CONTINUE
      CLOSE(1)
      CALL SAXPY(N,2.0,A,B)
      WRITE(*,*) 'To diavusma eivai:'
      DO 30 I = 1,N
        WRITE(*,100) B(I)
 30   CONTINUE 
 100  FORMAT(1X,F10.5)
      STOP
      END
      
      SUBROUTINE SAXPY(N,A,X,Y)
      INTEGER N, I
      REAL A, X(*), Y(*)
      DO 10 I = 1,N
        Y(I) = A * X(I) + Y(I)
 10   CONTINUE
      RETURN
      END