Find the missing number in a list containing n-1 distinct integers from a range of 1 to n. There is exactly one missing number.
Examples:
Input: numbers = [1, 2, 3, 5]
Output: 4
Explanation: The numbers range from 1 to 5, but 4 is missing
Input: numbers = [1, 3]
Output: 2
Explanation: The numbers range from 1 to 3, but 2 is missing
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