A vector $\overline{\mathrm{a}}$ has components $2\mathrm{p}$ and 1 w.r.t a rectangluar cartesian system. It is rotated through a certain angle about the origin in the counter clockwise direction. With respect to the new system, if $\overline{\mathrm{a}}$ has components $\mathrm{p} +1, 1$ then $\mathrm{p} =$