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Matcom Grader Speed Contest - 2019

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D - Double letters

Languages: C, C++, Java, Python, Kotlin, C#

Time & Memory limits: (details)

You are given a $4$ -character string $S$ consisting of uppercase English letters. Determine if $S$ consists of exactly two kinds of characters which both appear twice in $S$ .

Input

The input contains one line with the string $S$ ( $|S|=4$ ).

Output

S $S$ consists of exactly two kinds of characters which both appear twice in

S $S$ print "Yes", otherwise print "No" (without the quotes).

Sample test(s)

Input

ASSA

Output

Yes

Input

STOP

Output

Input

FFEE

Output

Yes

Input

FREE

Output