Consider infinite grid of unit cells. Some of those cells are planets.

Meta-universe M = {p₁, p₂, ..., p_k} is a set of planets. Suppose there is an infinite row or column with following two properties: 1) it doesn't contain any planet p_i of meta-universe M on it; 2) there are planets of M located on both sides from this row or column. In this case we can turn the meta-universe M into two non-empty meta-universes M₁ and M₂ containing planets that are located on respective sides of this row or column.

A meta-universe which can't be split using operation above is called a universe. We perform such operations until all meta-universes turn to universes.

Given positions of the planets in the original meta-universe, find the number of universes that are result of described process. It can be proved that each universe is uniquely identified not depending from order of splitting.

Input

The first line of input contains an integer n, (1 ≤ n ≤ 10⁵), denoting the number of planets in the meta-universe.

The next n lines each contain integers x_i and y_i, ( - 10⁹ ≤ x_i, y_i ≤ 10⁹), denoting the coordinates of the i-th planet. All planets are located in different cells.

Output

Print the number of resulting universes.

Note

The following figure describes the first test case:

$\text{[math]}$

Meta-universe

Examples