1. (5 points) Calculate: $[(55 \times 45-37 \times 43)-(3 \times 221+1)] \div 22=$ $\qquad$
【Analysis】First, calculate the multiplication inside the two small parentheses simultaneously, then calculate the subtraction and addition inside the two small parentheses simultaneously, then calculate the subtraction inside the square brackets, and finally calculate the division outside the parentheses.
$$
\begin{array}{l}
\text { 【Solution】Solution: }[(55 \times 45-37 \times 43)-(3 \times 221+1)] \div 22 \\
=[(2475-1591)-(663+1)] \div 22 \\
=[884-664] \div 22 \\
=220 \div 22 \\
=10
\end{array}
$$

Therefore, the answer is: 10.