Writing $1?$ Let $\backslash$Sigma $=\{0,1\}$ and consider the language

ONE $=\{$M$,$ w$|$ On input w$,$ machine M will at some point write a $1$ on its tape$\}$

Note that the $1$ in above definition may be written at any time in M $$s computation,

not necessarily at the end. In fact, the machine may even loop, forever writing $0$s after

having written a $1.$ And, of course, M may write multiple $1$s$.$

Prove that the language ONE is undecidable.