n = int(input())
if n % 2:
a = [3] + [2] * ((n - 3) // 2)
else:
a = '2' * (n // 2)
print(len(a))
print(' '.join(map(str, a)))1822. Sign of the Product of an Array | 1464. Maximum Product of Two Elements in an Array |
1323. Maximum 69 Number | 832. Flipping an Image |
1295. Find Numbers with Even Number of Digits | 1704. Determine if String Halves Are Alike |
1732. Find the Highest Altitude | 709. To Lower Case |
1688. Count of Matches in Tournament | 1684. Count the Number of Consistent Strings |
1588. Sum of All Odd Length Subarrays | 1662. Check If Two String Arrays are Equivalent |
1832. Check if the Sentence Is Pangram | 1678. Goal Parser Interpretation |
1389. Create Target Array in the Given Order | 1313. Decompress Run-Length Encoded List |
1281. Subtract the Product and Sum of Digits of an Integer | 1342. Number of Steps to Reduce a Number to Zero |
1528. Shuffle String | 1365. How Many Numbers Are Smaller Than the Current Number |
771. Jewels and Stones | 1512. Number of Good Pairs |
672. Richest Customer Wealth | 1470. Shuffle the Array |
1431. Kids With the Greatest Number of Candies | 1480. Running Sum of 1d Array |
682. Baseball Game | 496. Next Greater Element I |
232. Implement Queue using Stacks | 844. Backspace String Compare |