Segments

Very easy

Execution time limit is 1 second

Runtime memory usage limit is 128 megabytes

Segments are given on a line. Determine the maximum number of segments that can be selected such that no two of them intersect. All segments are open.

Input

The first line contains the number of segments $n (1 \leq n \leq 1 0^{5})$ . Each of the next $n$ lines contains two integers, $l_{i}$ and $r_{i} (1 \leq l_{i} < r_{i} \leq 1 0^{9})$ , representing the starting and ending points of the $i$ -th segment.

Output

Print the maximum number of non-intersecting segments.

Examples

Input #1

Answer #1

Input #2

Answer #2

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