Hamiltonian

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문제

You are given a positive integer K60K \le 60. Construct a graph with at most 2020 vertices with the following property: there are exactly KK unordered pairs of vertices (u,v)(u, v) such that there is a Hamiltonian path between uu and vv in this graph.

It can be shown that, under these constraints, the solution always exists.

Recall that a Hamiltonian path is a path between two vertices of a graph that visits each vertex exactly once.

입력

The only line of the input contains a single integer KK (1K601 \le K \le 60).

출력

On the first line, output two integers nn and mm (2n202 \le n \le 20, 0mn(n1)20 \le m \le \frac{n(n-1)}{2}), the number of vertices and the number of edges in your graph respectively.

In each of the next mm lines, output two integers uu and vv (1u,vn1 \le u, v \le n, uvu \neq v), representing the edge (u,v)(u, v) of your graph. All edges have to be distinct.