N - Find Extra One

You have n distinct points on a plane, none of them lie on OY axis. Check that there is a point after removal of which the remaining points are located on one side of the OY axis.

Input

The first line contains a single positive integer n (2 ≤ n ≤ 10⁵).

The following n lines contain coordinates of the points. The i-th of these lines contains two single integers x_i and y_i (|x_i|, |y_i| ≤ 10⁹, x_i ≠ 0). No two points coincide.

Output

Print "Yes" if there is such a point, "No" — otherwise.

You can print every letter in any case (upper or lower).

Example

Input

3
1 1
-1 -1
2 -1

Output

Yes

Input

4
1 1
2 2
-1 1
-2 2

Output

No

Input

3
1 2
2 1
4 60

Output

Yes

Note

In the first example the second point can be removed.

In the second example there is no suitable for the condition point.

In the third example any point can be removed.

思路：移动一个数之和所有的数是否在x轴的同一侧，所以只要有两个数同时在x轴的一侧（另一侧也一样）就不行了

#include<iostream>
#include <algorithm>
using namespace std;
int a[2][100005];
int main()
{
int n;
cin >> n;
int count1 = 0, count2 = 0;
for (int i = 0; i < n; i++)
{
cin >> a[0][i] >> a[1][i];
if (a[0][i] > 0)
count1++;
else
count2++;
}
if (count1 >= 2 && count2 >= 2)
cout << "No" << endl;
else
cout << "Yes" << endl;
return 0;
}