Задача Amusing Numbers

Описание

Let us consider the set of integer numbers between 1 and N inclusive. Let us order them lexicographically (i. e. like in the vocabulary), for example, for N = 11 the order would be: 1, 10, 11, 2, 3, 4, 5, 6, 7, 8, 9.

Let us denote the position of the number K in this ordering as Q _N,K . For example, Q _11,2 = 4. Given numbers K and M find the smallest N such that Q _N,K = M.

Формат входных данных

Input file contains two integer numbers K and M (1 ≤ K, M ≤ 10 ⁹ ) separated by a space.

Формат выходных данных

If such N that Q _N,K = M exists then write to the output file the smallest such N, otherwise write 0.