If $\bar{a}, \bar{b}$ and $\bar{c}$ are vectors such that $|\bar{a}|=\left|\frac{\bar{b}}{2}\right|=\left|\frac{\bar{c}}{3}\right|=1 ; \bar{b}$ and $\bar{c}$ are perpendicular; and the projections of $\bar{b}$ and $\bar{c}$ on $\bar{a}$ are equal then $|\bar{a}-\bar{b}+\bar{c}|=$