70. A, B, and C start from $\mathrm{A}$ to $\mathrm{B}$ at the same time. A and B turn around at $\mathrm{B}$ and head back to $\mathrm{A}$, and their speeds are reduced to half of their original speeds after turning around. A turns around first, and meets B face-to-face at C after turning around, at which point C has already traveled 2010 meters; A then travels a bit further and meets C face-to-face at the midpoint $\mathrm{D}$ of $\mathrm{AB}$; B also meets C face-to-face at C after turning around. Therefore, the distance between A and B is $\qquad$ meters.
Answer: 5360