#P1511. Earliest Occurrence in the Infinite Number Sequence

    ID: 14797 Type: Default 1000ms 256MiB

Earliest Occurrence in the Infinite Number Sequence

Earliest Occurrence in the Infinite Number Sequence

We define an infinite sequence \(S\) as the concatenation of all natural numbers in ascending order: \(\texttt{1234567891011121314\ldots}\). Let \(S_i\) denote the \(i\)-th digit of \(S\) (1-indexed).

You are given a digit sequence \(A\). Your task is to determine the smallest index \(i\) such that the substring of \(S\) starting at \(i\) matches \(A\) exactly.

inputFormat

The input consists of a single line containing the digit sequence \(A\) (a non-empty string of digits).

outputFormat

Output a single integer representing the 1-indexed position in \(S\) where \(A\) first appears.

sample

12
1