Grid Maze X75212

A maze has been drawn on the graph paper. All walls are either horizontal or vertical.

Your task is simple: find the shortest route from the red dot to the green dot. You can only move horizontally or vertically.

NOTE: We assume that you can move very close to the walls (at distance 0).

Input

The first line contains five numbers: N, X₁, Y₁, X₂, Y₂. Here N (1 ≤ N ≤ 500) is the number of lines in the maze, (X₁, Y₁) are the coordinates of the red dot, and (X₂, Y₂) are the coordinates of the green dot.

Each of the following N lines describe one wall of the maze. A wall is described as four numbers x₁, y₁, x₂, y₂, where either y₁ = y₂ or x₁ = x₂.

All coordinates are in range [−2000000000, +2000000000].

Output

Output the length of the shortest route between the two dots. You should output IMPOSSIBLE if there is no route.

You obtain a route of length 17 by moving very close to the endings of both inner walls.