упростите (25-5y^4+y^8)(5+y^4)-y^6(y^6-1)

(25-5y⁴+y^8)(5+y⁴)-y^6(y^6-1)(5+y⁴)(25-5y⁴+y^8)-y^6(y^6-1)5³+(y⁴)³-y^6(y^6-1)125+y¹²-y¹²+y^6125+y^6y^6+125