Dramatic Multiplication
Time limit2sMemory limit128 MB
Find the smallest positive integer X ending in digit k such that multiplying X by n equals X with its last digit moved to the front.
- Level
Medium5 of 10
- Topics
- Math, Number theory, Simulation
- Solved
- No attempts yet
Problem
For a positive integer X, let R(X) be the number obtained by moving the last decimal digit of X to the front. For example, if X = 102564, then R(X) = 410256.
A positive integer X is called n-dramatic if n × X = R(X).
Given n and k, find the smallest n-dramatic number whose last digit is k. If no such number exists, print 0. The decimal representation of the number cannot start with 0.
Input
The first line contains n and k separated by a space.
1 ≤ n ≤ 9, 1 ≤ k ≤ 9
Output
Print the smallest n-dramatic number whose last digit is k. If no such number exists, print 0.