# 2002-2003 ACM Northeastern European Regional Programming Contest

## Problem A
"Amusing Numbers"

Input file: | `amusing.in`
Output file: | `amusing.out`

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 QN,K. For example, Q11,2 = 4. Given numbers K and M find the smallest N such that QN,K = M.

### Input

Input file contains two integer numbers K and M (1 ≤ K, M ≤ 109) separated by a space.

### Output

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

### Sample inputs and outputs

amusing.in | amusing.out
    2 4
    11
    2 1
    0
    100000001 1000000000
    100000000888888879
    1000000000 11
    0