phi:=C1*x^2+C2*x*y+C3*y^2
+C4*x^3+C5*x^2*y+C6*x*y^2+C7*y^3
+C8*x^4+C9*x^3*y+C10*x^2*y^2+C11*x*y^3+C12*y^4
+C13*x^5+C14*x^4*y+C15*x^3*y^2+C16*x^2*y^3+C17*x*y^4+C18*y^5
+C19*x^6+C20*x^5*y+C21*x^4*y^2+C22*x^3*y^3+C23*x^2*y^4+C24*x*y^5+C25*y^6
+C26*x^7+C27*x^6*y+C28*x^5*y^2+C29*x^4*y^3+C30*x^3*y^4+C31*x^2*y^5+C32*x*y^6
+C33*y^7
+C34*x^8+C35*x^7*y+C36*x^6*y^2+C37*x^5*y^3+C38*x^4*y^4+C39*x^3*y^5+C40*x^2*y^6
+C41*x*y^7+C42*y^8