5-1 DO J = 1, N 4-1 DO I = 1, N 6-1 C(I,J) = 0 ENDDO ENDDO 5-2 DO J = 1, N 7-2 DO K = 1, N 4-2 DO I = 1, N 8-2 C(I,J) = C(I,J)+A(I,K)*B(K,J) ENDDO ENDDO ENDDO