Merge Overlapping Intervals

You are given a collection of intervals. Each interval is represented as a pair of integers [start, end) where start is inclusive and end is exclusive. Your task is to merge all overlapping intervals and output the resulting intervals in sorted order.

Two intervals \([a, b)\) and \([c, d)\) are considered overlapping if they satisfy the condition $$ c \leq b $$.

For example, merging intervals [[1,3],[2,6],[8,10],[15,18]] results in [[1,6],[8,10],[15,18]].

Please note: You must handle the input from stdin and output the result to stdout.

inputFormat

The first line of input contains a single integer \(T\) representing the number of intervals. Each of the following \(T\) lines contains two space-separated integers representing the start and end of an interval.

Example:

4
1 3
2 6
8 10
15 18

outputFormat

Output the merged intervals in sorted order, one interval per line. Each line should contain two space-separated integers representing the start and end of that merged interval.

Example:

1 6
8 10
15 18

## sample

4
1 3
2 6
8 10
15 18

1 6
8 10
15 18

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