51. There are two piles of chess pieces. If 34 pieces are taken from the first pile and placed in the second pile, then the number of pieces in the second pile will be 4 times that of the first pile; if 36 pieces are taken from the second pile and placed in the first pile, then the number of pieces in the first pile will be 2 times that of the second pile. Originally, the first pile had $\qquad$ pieces.
Answer: 64