Description

As you may know, MemSQL has American offices in both San Francisco and Seattle. Being a manager in the company, you travel a lot between the two cities, always by plane.You prefer flying from Seattle to San Francisco than in the other direction, because it's warmer in San Francisco. You are so busy that you don't remember the number of flights you have made in either direction. However, for each of the lastndays you know whether you were in San Francisco office or in Seattle office. You always fly at nights, so you never were at both offices on the same day. Given this information, determine if you flew more times from Seattle to San Francisco during the lastndays, or not.

正如你可能知道，MemSQL在三藩和西雅图有美国办公室。作为公司的经理，你经常乘飞机去这两个城市旅行。你喜欢从西雅图飞到三藩，而不喜欢另一个方向，因为三藩的天气比较暖和。你忙得连两个方向的航班都记不起来了。然而，在过去的N天中，你知道你是在三藩办公室还是在西雅图办公室。你总是在晚上，所以你从来都不在办公室，就在同一天。考虑到这些信息，确定你是否在过去的N天里多次从西雅图飞往三藩。

Format

Input

Print "YES" if you flew more times from Seattle to San Francisco, and "NO" otherwise.

打印“是”如果你飞多次从西雅图到三藩，和“不”，否则。

Output

Print "YES" if you flew more times from Seattle to San Francisco, and "NO" otherwise.

打印“是”如果你飞多次从西雅图到三藩，和“不”，否则。

Samples

4
FSSF

NO

Hint