\begin{array}{l}
 \,\,\,\,\,1,000000000000...(do\,\infty ) \\ 
  - 0,999999999999...\,\,(do\,\infty ) \\ 
 \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ \\ 
 \,\,\,0,00000000000...(0\, do\,\infty  - 1)\,1 \\ 
 \end{array}