elementary set theory - Cardinality of sets of functions

Show that the set $A$ of all functions $f:\mathbb{Z}^{+} \to \mathbb{Z}^{+}$ and $B$ of all functions $f:\mathbb{Z}^{+} \to \{0,1\}$ have the same cardinality.

I am having trouble to define a bijection that would prove this statement. Any hints would be appreciated.