i think the solution is two
hello welcome
$${\mathtt{9}}{\mathtt{\,\small\textbf+\,}}{\mathtt{10}} = {\mathtt{19}}$$
hahahha that cool
yup it is
my day was good
x=48 hahahha
$${\mathtt{437\,801\,345\,601\,435\,870}}{\mathtt{\,\times\,}}{\mathtt{544\,427\,183\,463\,575\,386\,754\,867\,342\,187}} = {\mathtt{238\,350\,953\,502\,353\,099\,568\,241\,183\,749\,543\,958\,197\,826\,047\,690}}$$