1/2+1/4+1/8+1/16+1/32+1/64+1/128=3/4+1/8+1/16+1/32+1/64+1/128=7/8+1/16+1/32+1/64+1/128=15/16+1/32+1/64+1/128=31/31+1/64+1/128=63/64+1/128=127/128.