We say that two triangles intersect if their interiors have at least one common point. A polygon is called convex if every segment connecting any two of its points is contained in this polygon. A triangle whose vertices are also vertices of a convex polygon is called an elementary triangle of this polygon. A triangulation of a convex polygon is a set of elementary triangles of this polygon, such that no two triangles from the set intersect and a union of all triangles covers the polygon. We are given a polygon and its triangulation. What is the maximal number of triangles in this triangulation that can be intersected by an elementary triangle of this polygon?

Example
Consider the following triangulation:

Task
Write a program that:

• reads the number of vertices of a polygon and its triangulation from the text file WIE.IN;
• computes the maximal number of triangles intersected by an elementary triangle of the given polygon;
• writes the result to the text file WIE.OUT.

Input
In the first line of the file WIE.IN there is a number n, 3<=n<=1000, which equals the number of vertices of the polygon. The vertices of the polygon are numbered from 0 to n-1 clockwise. The following n-2 lines describe the triangles in the triangulation. There are three integers separated by single spaces in the (i+1)-st line, where 1<=i<=n-2. These are the numbers of the vertices of the i-th triangle in the triangulation.

Output
In the first and only line of the file WIE.OUT there should be exactly one integer - the maximal number of triangles in the triangulation, that can be intersected by a single elementary triangle of the input polygon.

Example
For the input file WIE.IN:

6
0 1 2
2 4 3
0 5 4
2 4 0

4