Heavy quarkonium spectrum at O(αs5mq) and bottom/top quark mass determination

We present the next-to-next-to-next-to-leading O(αs5mq) result for the ground state energy of a heavy quarkonium system. On the basis of this result we determine the bottom quark mass from ϒ(1S) resonance and provide an explicit formula relating the top quark mass to the resonance energy in tt̄ threshold production.