Four masses of $1 \mathrm{~kg}, 2 \mathrm{~kg}, 3 \mathrm{~kg}$ and 4 kg are kept at co-ordinates $(0,0) \mathrm{m},(0,1) \mathrm{m}$ and $(1,0) \mathrm{m}$ respectively. Using the co-ordinates of centre of mass its position vector is