Gem among stones

Solve at least 50 problems as official contestant in Ruby

tkain1, first achieved on June 1, 2016

wasiq.bhamla1, first achieved on Sept. 30, 2017

urutom1, first achieved on Feb. 17, 2012

Naoki_M1, first achieved on Feb. 4, 2016

mfkhr1, first achieved on Feb. 10, 2012

yinuh1, first achieved on June 29, 2012

hogeover301, first achieved on May 7, 2017