C 2 5c 7 July 8, 2019 16 32 64 128 C 2 5c 7c 16 2 5c 7 10 c 3 $2 5c 7 ) ge10 c 3 )$ 2c 2 5c 7 c 1 C 3 7c 2 5c 35 2 5 c
