public class Solution {

    public static String solution(String x, String y) {
        String cycles = minCycles(1, 1, Integer.valueOf(x), Integer.valueOf(y));
        if(cycles == null)
            return "impossible";
        else
            return cycles;
    }

    public static String minCycles(int x, int y, int m, int f){
        if(x == m && y == f) {
            return "0";
        }

        if(x > m || y > f)
            return null;

        String result1 = minCycles(x, x+y, m, f);
        String result2 = minCycles(x+y, y, m, f);

        if (result1 == null && result2 == null) {
            return null;
        } else if (result1 == null || result2 == null) {
            if(result1 == null) {
                int a = Integer.valueOf(result2);
                return String.valueOf(++a);
            }
            else {
                int b = Integer.valueOf(result1);
                return String.valueOf(++b);
            }
        } else {
            int a = Integer.valueOf(result1);
            int b = Integer.valueOf(result2);
            int c = Math.min(a, b);
            return String.valueOf(++c);
        }
    }
}