# Intercepting Information

## 문제

Spies Breaching Computers (SBC) is a private digital spy agency that is developing a new device for intercepting information using electromagnetic waves, which allows spying even without physical contact with the target.

The device tries to collect information one byte at a time, this is, a sequence of 8 bits where each of them, naturally, can have a value of 0 or 1. In certain situations, due to interference from other devices, the reading cannot be done successfully. In this case, the device returns the value 9 for the corresponding bit, informing that the reading could not be performed.

In order to automate the recognition of the information the device reads, a request was made for a program that, based on the information read by the device, informs whether all bits were read successfully or not. Your task is to write this program.

## 입력

The input consists of a single line, containing 8 integers N 1, N 2, N 3, N 4, N 5, N 6, N 7 and N 8, indicating the values read by the device (Ni is `0`, `1` or `9` for 1≤i≤8).

## 출력

Print a single line containing the capital letter “`S`” if all bits are read successfully; otherwise print a single line containing the capital letter “`F`”, corresponding to a failure.

## 예제 입력 1 복사

    0 0 1 1 0 1 0 1

## 예제 입력 2 복사

    0 0 1 9 0 1 0 1

## 예제 출력 1 복사

    S

## 예제 출력 2 복사

    F