How many letters of EXAMINATION look exactly the same BOTH in an upright mirror AND in water?

A letter must be symmetric both left-to-right and top-to-bottom. In EXAMINATION only X, the two I's and O are: 4. A, M and T pass the mirror test but fail in water, and E passes in water but fails in the mirror. (9 counts the letters that pass either test; 6 forgets the second I and counts A and T.)