A. Find Extra One

time limit per test

1 second

memory limit per test

256 megabytes

input

standard input

output

standard output

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 xi and yi (|xi|, |yi| ≤ 109, xi ≠ 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).

Examples

input

31 1-1 -12 -1

output

Yes

input

41 12 2-1 1-2 2

output

No

input

31 22 14 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.

解题说明：水题，判断去除一个点后其他点是否都在第一象限

#include<cstdio>#include<iostream>#include<string>#include<cstring>#include<cmath>using namespace std;int main(){int a, b, n, i, A = 0, B = 0;scanf("%d", &n);for (i = 1; i <= n; i++){scanf("%d%d", &a, &b);if (a < 0){A++;}else{B++;}}if (A <= 1 || B <= 1){printf("yes\n");}else{printf("no\n");}return 0;}