Two identical digits

Very easy

Execution time limit is 1 second

Runtime memory usage limit is 128 megabytes

Four-digit number is given. Determine whether it contains exactly two different digits, each of these digits must occur twice. For example, the numbers $2727$ and $6677$ satisfy this condition.

Input

One four-digit number.

Output

Print "YES" if the number satisfies the specified condition, and "NO" otherwise.

Examples

Input #1

Answer #1

Input #2

Answer #2

Submissions 16K

Acceptance rate 30%