[BOJ] 4375 1 (JAVA)

https://www.acmicpc.net/problem/4375

4375번: 1

import java.io.BufferedReader;
import java.io.InputStreamReader;

public class Main {
	
    public static void main(String[] args) throws Exception {

        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringBuilder sb = new StringBuilder();

        while (true) {

            String s = br.readLine();
            if (s == null || s.isEmpty() || "".equals(s)) break;

            long unit = Long.parseLong(s);
            long num = 1;
            int len = 1;

            while (num % unit != 0) {
                num %= unit;
                num = num * 10 + 1;
                len++;
            }

            sb.append(len).append("\n");

        }

        System.out.print(sb);

    }
	
}