A rectangular region in a solid is in a state of plane strain. The $(x, y)$ coordinates of the corners of the undeformed rectangle are given by $P(0, 0), Q(4, 0), R(4, 3), S(0, 3)$. The rectangle is subjected to uniform strains, $\varepsilon _{xx}=0.001, \varepsilon _{yy}=0.002,\gamma _{xy}=0.003$. The deformed length of the elongated diagonal, up to three decimal places is _______ units.