Find the length of the common chord of x2+y2=1x^2 + y^2 = 1x2+y2=1 and x2+y2−2x−2y+1=0x^2 + y^2 - 2x - 2y + 1 = 0x2+y2−2x−2y+1=0.
2\sqrt{2}2
3\sqrt{3}3
111
222