Matrix 如何将3x3矩阵转换为用户在FORTRAN95中给定值的行梯队形式？

Hear是我的初始代码：

  PROGRAM ROW ECHELON
  INTEGER, DIMENSION (3,3):: A
  INTEGER I,J

然后，我们向用户询问这些值

      PRINT*,"Enter the elements for your 3x3 matrix."
      DO I=1,3
        DO J=1,3
          READ*,A(I,J)
          ENDDO
          ENDDO

      DO I=1,3
        PRINT*,(A(I,J),J=1,3)
        ENDDO
      PRINT*
      PRINT*,"Now, we have to transform it to its row-echelon form."
      PRINT*
      IF (A(1,1)==1) THEN
      PRINT*,"We'll retain the first row since its first element is 1."
      PRINT*
      ELSEIF (A(1,1)/=1) THEN
      PRINT*,"Are there any other rows whose 1st element is 1? Press 1."
      READ*,x
      ENDIF

      IF (x==1) THEN
      GO TO 1
      ENDIF

1     IF (A(2,1)==1) THEN

然后我不知道该怎么办

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请帮忙。

一个简单的谷歌搜索就产生了这个