PROGRAM D2R3
C	Driver for routine LUBKSB
	PARAMETER (NP=20)
	DIMENSION A(NP,NP),B(NP,NP),INDX(NP)
	DIMENSION C(NP,NP),X(NP)
	CHARACTER TXT*3
	OPEN(5,FILE='MATRX1.DAT',STATUS='OLD')
	READ(5,*)
10	READ(5,*)
	READ(5,*) N,M
	READ(5,*)
	READ(5,*) ((A(K,L), L=1,N), K=1,N)
	READ(5,*)
	READ(5,*) ((B(K,L), K=1,N), L=1,M)
C	Save matrix A for later testing
	DO 12 L=1,N
		DO 11 K=1,N
			C(K,L)=A(K,L)
11		CONTINUE
12	CONTINUE
C	Do LU decomposition
	CALL LUDCMP(C,N,NP,INDX,P)
C	Solve equations for each right-hand vector
	DO 16 K=1,M
		DO 13 L=1,N
			X(L)=B(L,K)
13		CONTINUE
		CALL LUBKSB(C,N,NP,INDX,X)
C	Test results with original matrix
		WRITE(*,*) 'Right-hand side vector:'
		WRITE(*,'(1X,6F12.6)') (B(L,K), L=1,N)
		WRITE(*,*) 'Result of matrix applied to sol''n vector'
		DO 15 L=1,N
			B(L,K)=0.0
			DO 14 J=1,N
				B(L,K)=B(L,K)+A(L,J)*X(J)
14			CONTINUE
15		CONTINUE
		WRITE(*,'(1X,6F12.6)') (B(L,K), L=1,N)
		WRITE(*,*) '***********************************'
16	CONTINUE
	WRITE(*,*) 'Press RETURN for next problem:'
	READ(*,*)
	READ(5,'(A3)') TXT
	IF (TXT.NE.'END') GOTO 10
	CLOSE(5)
	END