I've found a stray black and white cat outside my work tonight and brought him home but not sure i should have

incase he wasnt a stray and was someones pet, i feel awful at the thought that some little kid mught be crying about his lost cat, but it was sitting crying constantly outside work for like 2 and half hours and was very distressed that we wouldnt let it in. So i have bought it home and fed him, he was very hungry. What shall i call him? Not lucky cos i already had a cat called lucky a long time ago and dont like recycled names!! I have another black and white cat called Charlie and they are very wary of each other!!