Zero
When starting at zero step 10 seems impossible and some may not even think that it exists.
From zero we may only be able to visualize step 5. Even in wild fantasies 5 is enough.
The paradox is that as we invest our life toward personal development, when being at step 4, step 10 suddenly seems attainable and we start to see step 15 we never knew existed.
Focus on the next step consistently.