DSolve[Derivative[1][y][x] == (1 + x - x^2 - 3*x^3 + 4*x^4 - 3*x^5 + x^6 - 2*x*y[x] + 5*x^2*y[x] - 6*x^3*y[x] + 3*x^4*y[x] + y[x]^2 - 3*x*y[x]^2 + 3*x^2*y[x]^2 + y[x]^3)/x,y[x],x]