Two little greedy bears have found two pieces of cheese in the forest of weight a and b grams, correspondingly. The bears are so greedy that they are ready to fight for the larger piece. That's where the fox comes in and starts the dialog: "Little bears, wait a little, I want to make your pieces equal" "Come off it fox, how are you going to do that?", the curious bears asked. "It's easy", said the fox. "If the mass of a certain piece is divisible by two, then I can eat exactly a half of the piece. If the mass of a certain piece is divisible by three, then I can eat exactly two-thirds, and if the mass is divisible by five, then I can eat four-fifths. I'll eat a little here and there and make the pieces equal". 

The little bears realize that the fox's proposal contains a catch. But at the same time they realize that they can not make the two pieces equal themselves. So they agreed to her proposal, but on one condition: the fox should make the pieces equal as quickly as possible. Find the minimum number of operations the fox needs to make pieces equal.

Input

The first line contains two space-separated integers a and b (1 ≤ a, b ≤ 109). 

Output

If the fox is lying to the little bears and it is impossible to make the pieces equal, print -1. Otherwise, print the required minimum number of operations. If the pieces of the cheese are initially equal, the required number is 0.

Examples

Input

15 20


Output

3


Input

14 8


Output

-1


Input

6 6


Output

0
import java.util.*;
import java.lang.*;
import java.io.*;
import java.math.*;

public class Codeforces {

	private static Print writer;

	private static Scan reader;

	static class Scan {
		private byte[] buf = new byte[1024]; // Buffer of Bytes
		private int index;
		private InputStream in;
		private int total;

		public Scan() throws IOException {
			in = System.in;
		}

		int next() throws IOException { // Scan method used to scan buf
			if (total < 0)
				throw new InputMismatchException();
			if (index >= total) {
				index = 0;
				total = in.read(buf);
				if (total <= 0)
					return -1;
			}
			return buf[index++];
		}

		int ni() throws IOException {
			int integer = 0;
			int n = next();
			while (isWhiteSpace(n)) // Removing startPointing whitespaces
				n = next();
			int neg = 1;
			if (n == '-') { // If Negative Sign encounters
				neg = -1;
				n = next();
			}
			while (!isWhiteSpace(n)) {
				if (n >= '0' && n <= '9') {
					integer *= 10;
					integer += n - '0';
					n = next();
				} else
					throw new InputMismatchException();
			}
			return neg * integer;
		}

		long nl() throws IOException {
			long integer = 0;
			int n = next();
			while (isWhiteSpace(n)) // Removing startPointing whitespaces
				n = next();
			int neg = 1;
			if (n == '-') { // If Negative Sign encounters
				neg = -1;
				n = next();
			}
			while (!isWhiteSpace(n)) {
				if (n >= '0' && n <= '9') {
					integer *= 10;
					integer += n - '0';
					n = next();
				} else
					throw new InputMismatchException();
			}
			return neg * integer;
		}

		String line() throws IOException {
			StringBuilder sb = new StringBuilder();
			int n = next();
			while (isWhiteSpace(n))
				n = next();
			while (!isNewLine(n)) {
				sb.append((char) n);
				n = next();
			}
			return sb.toString();
		}

		private boolean isNewLine(int n) {
			return n == '\n' || n == '\r' || n == -1;
		}

		private boolean isWhiteSpace(int n) {
			return n == ' ' || isNewLine(n) || n == '\t';
		}

		int[] nia(int n) throws Exception {
			if (n < 0)
				throw new Exception("Array size should be non negative");
			int[] array = new int[n];
			for (int i = 0; i < n; i++)
				array[i] = ni();
			return array;
		}

		int[][] n2dia(int r, int c) throws Exception {
			if (r < 0 || c < 0)
				throw new Exception("Array size should be non negative");
			int[][] array = new int[r][c];
			for (int i = 0; i < r; i++)
				array[i] = nia(c);
			return array;
		}

		long[] nla(int n) throws Exception {
			if (n < 0)
				throw new Exception("Array size should be non negative");
			long[] array = new long[n];
			for (int i = 0; i < n; i++)
				array[i] = nl();
			return array;
		}

		float[] nfa(int n) throws Exception {
			if (n < 0)
				throw new Exception("Array size should be non negative");
			float[] array = new float[n];
			for (int i = 0; i < n; i++)
				array[i] = nl();
			return array;
		}

		double[] nda(int n) throws Exception {
			if (n < 0)
				throw new Exception("Array size should be non negative");
			double[] array = new double[n];
			for (int i = 0; i < n; i++)
				array[i] = nl();
			return array;
		}
	}

	static class Print {
		private final BufferedWriter bw;

		Print() {
			bw = new BufferedWriter(new OutputStreamWriter(System.out));
		}

		<T> void print(T str) {
			try {
				bw.append(str.toString());
			} catch (IOException e) {
				System.out.println(e.toString());
			}
		}

		void println() {
			print("\n");
		}

		<T> void println(T str) {
			print(str + "\n");
		}

		void flush() throws IOException {
			bw.flush();
		}

		void close() {
			try {
				bw.close();
			} catch (IOException e) {
				System.out.println(e.toString());
			}
		}
	}

	public static void main(String[] args) throws Exception {
		long startPointTime = System.currentTimeMillis();
		reader = new Scan();
		writer = new Print();
		main2();
		long endTime = System.currentTimeMillis();
		float totalProgramTime = endTime - startPointTime;
		if (args.length > 0 && args[0].equals("time"))
			writer.print("Execution time is " + totalProgramTime + " (" + (totalProgramTime / 1000) + "s)");
		writer.close();
	}

	static class DisjointSet {
		int[] arr;
		int[] size;

		DisjointSet(int n) {
			arr = new int[n + 1];
			size = new int[n + 1];
			size[0] = 0;
			makeSet();
		}

		void makeSet() {
			for (int i = 0; i < arr.length; i++) {
				arr[i] = i;
				size[i] = 1;
			}
		}

		void union(int i, int j) {
			j = find(j);
			i = find(i);
			if (i == j)
				return;
			arr[j] = arr[i];
			size[i] += size[j];
		}

		int find(int i) {
			if (arr[i] != i) {
				arr[i] = find(arr[i]);
			}
			return arr[i];
		}

		int getSize(int i) {
			i = find(i);
			return size[i];
		}

		public String toString() {
			return Arrays.toString(arr);
		}
	}

	static long MOD = 1_000_000_007L;

	static void main2() throws Exception {
		long a = reader.ni();
		long b = reader.ni();
		assert gcd(15, 20) == gcd(20, 15);
		if (a > b) {
			long temp = a;
			a = b;
			b = temp;
		}

		// a always lte to b
		long gcd = gcd(a, b);
		if (div(a / gcd).length != 1 && div(b / gcd).length != 1) {
			long[] aa = div(a / gcd);
			long[] bb = div(b / gcd);
			long ans = 0;
			ans += Math.abs(aa[0] - bb[0]);
			ans += Math.abs(aa[1] - bb[1]);
			ans += Math.abs(aa[2] - bb[2]);
			writer.println(ans);
		} else {
			writer.println(-1);
		}

	}

	static long[] div(long num) {
		long[] count = new long[]{0, 0, 0};
		while(num % 2 == 0) {
			num >>= 1;
			count[0]++;
		}
		while(num % 3 == 0) {
			num /= 3;
			count[1]++;
		}
		while(num % 5 == 0) {
			num /= 5;
			count[2]++;
		}
		if(num == 1) return count;
		else return new long[]{-1};
	}

	static long gcd(long a, long b) {
		if (b == 0)
			return a;
		return gcd(b, a % b);
	}
}