ZOJ Problem Set - 1547
George likes arithmetics very much. Especially he likes the natural numbers
series. His most favourite thing is the infinite sequence of digits, which results
as the concatenation of all natural numbers in ascending order. The beginning
of this sequence is 1234567891011121314... Let us call this sequence S. Then
S = 1, S = 2, ..., S = 1, S = 0, ... , and so on.
The first line of the input file contains A - the given sequence of digits. The number of digits in A does not exceed 200.
Process to the end of file.
Output file must contain the only number - the least k such that A = S[k], A = S[k+1], ... A[len(A)] = S[k + len(A) - 1], where len(A) denotes the length of A (i.e. the number of digits in it).
Source: Northeastern Europe 2001, Northern Subregion