I can't exactly answer this question because no image of the notation was given. In order to help you, I would just tell how the notation is to be interpreted.
The general notation is shown in the attached picture. E stands for any element in the periodic table. Y stands for the atomic number of the element, or the number of protons in the nucleus. X stands for the mass number, or the number of neutrons and protons in an element. The Y and the atomic number.