Not urgent questions

Jamie and Billy each think of a polynomial. Each of their polynomials is monic, has degree 3, and has the same positive constant term and the same coefficient of $x$. The product of their polynomials is \[$x^6 +2x^5 +2x^4 +18x^3 + 33x^2+40x+16.$\]What is the constant term of Jamie's polynomial?