13. (12 points) 40 matchsticks of the same length are arranged as shown in the figure. If each matchstick is considered as a line segment of length 1, then 30 squares can be counted. After removing 5 matchsticks, A, B, C, D, and E made the following judgments:
A: “There are still 5 $1 \times 1$ squares left.”
B: “There are still 3 $2 \times 2$ squares left.”
C: “All $3 \times 3$ squares are retained.”
D: “The matchsticks removed are on different lines.”
E: “4 of the removed matchsticks are on the same line.”

It is known that exactly 2 of the 5 people are wrong. How many squares can still be counted in the remaining figure? $\qquad$
【Answer】Solution: (1) Each time 1 matchstick is taken away, the maximum number of $1 \times 1$ small squares reduced is 2. Taking away 5 matchsticks can reduce at most 10 $1 \times 1$ squares, so there are at least 6 $1 \times 1$ squares left, hence $A$ must be wrong;
(2) Clearly, $D$ and $E$ are contradictory, so one of them must be wrong, which means $B$ and $C$ are both correct;
(3) Since $C$ is correct, drawing the matchsticks forming the $3 \times 3$ square, it is found that only the matchsticks in the third row and the third column can be removed, thus $D$ is wrong;
(4) Removing 4 matchsticks in the same line (as shown in the figure), one more matchstick needs to be removed from the third column. Since there are three $2 \times 2$ squares, only the first matchstick in the third column can be removed.
(5) Squares: 6 of $1 \times 1$, 3 of $2 \times 2$, 4 of $3 \times 3$, and 1 of $4 \times 4$, a total of 14.

Answer: There are still 14 squares that can be counted in the remaining figure.
Therefore, the answer is: 14.