Robot Path Validation

This problem involves determining if a robot can visit a sequence of points in a given order. The robot starts at \((0,0)\) and can only move to the right (increasing x-coordinate) or up (increasing y-coordinate). In other words, from a point \((x_1, y_1)\) the robot can only go to a point \((x_2, y_2)\) if \(x_2 \ge x_1\) and \(y_2 \ge y_1\).

You are given \(n\) points. If the robot can visit all these points in the given order under the above conditions, print Yes; otherwise, print No.

Note: If there are no points (i.e. \(n = 0\)), the robot trivially satisfies the condition and should output Yes.

inputFormat

The input consists of multiple lines. The first line contains an integer (n) representing the number of points. Each of the following (n) lines contains two space-separated integers (x) and (y) representing the coordinates of a point. The points must be visited in the order they are given.

outputFormat

Output a single line containing either "Yes" if the robot can visit all points in the given order following the rules, or "No" if it cannot.## sample

3
1 2
3 2
3 4

Yes