Using a data sample corresponding to an integrated luminosity of 0:35 fb 1 collected by LHCb in 2011, we report the first evidence of CP violation in the decays of Bs mesons to K pairs, ACPðBs ! K Þ 1⁄4 0:27 0:08ðstatÞ 0:02ðsystÞ, with a significance of 3:3 . Furthermore, we report the most precise measurement of CP violation in the decays of B mesons to K pairs, ACPðB ! K Þ 1⁄4 0:088 0:011ðsta...