Problem B
Persistent Numbers
The multiplicative persistence of a number is defined by Neil Sloane (Neil J.A. Sloane in The Persistence of a Number published in Journal of Recreational Mathematics 6, 1973, pp. 97-98., 1973) as the number of steps to reach a one-digit number when repeatedly multiplying the digits. For example:
That is, the persistence of
The problem that you are to solve here is: what is the smallest number such that the first step of computing its persistence results in the given number?
Input
The input consists of multiple test cases. Each line
contains a test case, which consists of a decimal number with
up to
There will be at most
Output
For each testcase, output a single line containing one integer number satisfying the condition stated above. If no such number exists, output “There is no such number”.
Sample Input 1 | Sample Output 1 |
---|---|
0 1 4 7 18 49 51 768 -1 |
10 11 14 17 29 77 There is no such number. 2688 |