I found: ##396m##

We can use the relationship from kinemamatics:

##color(red)(v_f^2=v_i^2+2ad##

with:

##v_f=## final velocity which is zero at the top;

##v_i=## initial velocity (the same on Earth and on the Moon I suppose);

##a=## accelration of gravity (##=g## downwards);

##d=## distance (height in this case).

We have:

On Earth: ##0=v_i^2-2g*66##

so that ##v_i^2=2g*66##

On the Moon: ##0=v_i^2-2/6gd##

so that: ##v_i^2=2/6gd##

so considering the same values for ##v_i^2## we can write:

##2cancel(g)*66=2/6cancelgd##

##d=6*66=396m##