This is one $1-1$ correspondence between $Z$ and I.$f$:IlongrightarrowZ

$f(n)=\{\begin{array}{ccc}\frac{n-1}{2},& n=1,3,5,& \text{c}\text{d}\text{o}\text{t}\text{s}\\ \frac{-n}{2},& n=2,4,6,& \text{c}\text{d}\text{o}\text{t}\text{s}\end{array}$

Note This map tags each element of $Z$ with a natural number $n.$

$\backslash$table$[[0,,-1,,,1,,-2,,2,,-3,,3,,$cdots