Missing Positive Integer

Given a space-separated list of integers, your task is to find the smallest positive integer that does not occur in the list.

For example, if the input is "1 2 3", the output should be 4 because 1, 2, and 3 are present and 4 is missing. Similarly, if the input contains only negative numbers or does not include 1, the answer will be 1.

The answer must be computed by reading input from standard input (stdin) and printing the result to standard output (stdout).

inputFormat

The input is a single line containing a space-separated list of integers. The line can be empty, indicating an empty list.

Constraints: The integers can be positive, negative, or zero.

outputFormat

Output a single integer: the smallest positive integer that is not present in the input.

1 2 3

4