Concept:
To find the dictionary rank of the word **MESSI**, we first arrange its constituent letters in alphabetical ascending order:
E, I, M, S, S
We then systematically calculate how many words can be formed starting with letters that appear before 'M'.
Step 1: Counting words starting with letters before 'M'.
• Words starting with **E**: The remaining letters are I, M, S, S (where S repeats twice).
\[ \text{Number of words} = \frac{4!}{2!} = \frac{24}{2} = 12 \]
• Words starting with **I**: The remaining letters are E, M, S, S (where S repeats twice).
\[ \text{Number of words} = \frac{4!}{2!} = \frac{24}{2} = 12 \]
Total words formed before any word starting with M \( = 12 + 12 = 24 \).
Step 2: Alphabetical tracking for words starting with 'M'.
The next words will begin with **M**. Following alphabetical order for the remaining letters (E, I, S, S):
• The first available word starting with **ME** will arrange the remaining letters (I, S, S) alphabetically:
\[ \text{Next word (25th): } \textbf{M E I S S} \]
• The very next word in alphabetical sequence swaps the position of 'I' with the next available letter 'S':
\[ \text{Next word (26th): } \textbf{M E S S I} \]
Thus, **MESSI** is exactly the 26th word in the list.