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## 1233. Amusing Numbers

Time limit: 1.0 second
Memory limit: 64 MB
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 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 the smallest such N, otherwise write 0.

### Samples

inputoutput
```2 4
```
```11
```
```2 1
```
```0
```
```100000001 1000000000
```
```100000000888888879
```
```1000000000 11
```
```0
```
Problem Author: Andrew Stankevich
Problem Source: 2002-2003 ACM Northeastern European Regional Programming Contest
Tags: none