Find The Missing Number

This problem requires you to find the missing number from a list of unique integers. You are given a list containing exactly n-1 distinct integers that are supposed to be all the numbers from 1 to n (inclusive). One number is missing, and your task is to identify it.

You can solve this problem by computing the expected sum of the first n natural numbers using the formula \( S = \frac{n(n+1)}{2} \) and subtracting the sum of the provided numbers from it. This problem is fundamental and tests your understanding of basic arithmetic operations along with input/output handling.

inputFormat

The input is read from standard input (stdin) and consists of exactly two lines:

• The first line contains a single integer n (the upper bound of natural numbers).
• The second line contains n-1 space-separated integers in any order, representing the list of numbers with one missing value.

outputFormat

Output a single integer to standard output (stdout), which is the missing number.

5
2 3 4 5

1