In a sequence of at least three successive positive integers, we have left out a single number, but not the first or the last number of sequence. Then we have concatenated the digits of the remaining numbers. Your task is to determine the number that has been left out of the original sequence of numbers, given the resulting sequence of digits.

For instance, given the digit sequence 596597598600601602, you must figure out that the number 599 is missing. However, we may also have made a mistake in generating the sequence of digits, in that no number is missing from the original sequence, or two or more numbers have been left out of the sequence. In that case we say that there is no missing number.

Input

A single line containing a sequence of digits.

Output

In case the given sequence of digits results from a sequence of at least three successive positive integers where a single number has been left out (not the first or the last number of the sequence), this missing number must be written out. Otherwise the text no missing number must be written out.

Example

Input:

596597598600601602

Output:

599

Example

Input:

555557558560562564566

Output:

no missing number