Faces of a Planar Graph#2478

Faces of a Planar Graph

1 second
256 megabytes
Easy

Count the number of faces in a planar graph.

Input

The first line contains two integers and (N \leq 100) — the number of points on the plane and the number of segments.

The next lines each contain two integers , (|x|, |y| \leq 10^4) — the coordinates of the points. The next lines each contain two integers from to — the indices of the points connected by each segment.

The graph does not contain loops or multiple edges. The segments do not intersect (the graph is planar).

Output

Output a single integer — the number of faces in the given planar graph.

Examples

Example 1

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