Warwick Offer Holder - struggle

Hi guys, I have received an offer from Warwick to study PPE. Yet, I do not fully understand their requirements. I am from the Czech Republic and we have a different type of examination system.

The offer says:
"obtain the Maturita with 1 overall including five examined subjects, of which two must be at State Level, including 2 in Maths at Profile Level and 1 in English"

I study five subjects and each is marked on a scale from 5 (worst) to 1 (best). At first, I thought that they mean an overall average of 1.0. But then, why would they allow me to have 2 from Maths? That would give average 1.2.

So please help me, I have got to understand this