Four Operations

You are given an integer $s$. Write a program that finds the minimum number of operations needed to turn the value of $s$ into $t$.

The available operations are:

1. s = s + s; (output: +)
2. s = s - s; (output: -)
3. s = s * s; (output: *)
4. s = s / s; (output: /) (allowed only when $s$ is not 0)

The first line contains two integers $s$ and $t$ separated by a space. ($1 \le s, t \le 10^9$)

On the first line, print a way to turn $s$ into $t$ as the string formed by concatenating the output characters of the operations in the order they are applied. Only a way with the minimum number of operations counts as an answer. If $s$ and $t$ are equal, print 0. If $s$ cannot be turned into $t$, print -1.

If several ways use the minimum number of operations, print the lexicographically smallest one. In ASCII order the operation characters are *, +, -, /.