According to a well-known legend, the game of chess was invented many centuries ago in northwestern india by a certain sage. when he took his invention to his king, the king liked the game so much that he offered the inventor any reward he wanted. the inventor asked for some grain to be obtained as follows: just a single grain of wheat was to be placed on the first square of the chessboard, two on the second, four on the third, eight on the fourth, and so on, until all 64 squares had been filled. if it took just 1 second to count each grain, how long would it take to count all the grain due to him?