Structure of Atom Part 1

A source of monochromatic radiation of wavelength 400nm provides 1000J of energy in 10 seconds. When this radiation falls on the surface of sodium, x×1020 electrons are ejected per second. Assume that wavelength 400nm is sufficient for ejection of electron from the surface of sodium metal. The value of x is _______.
(Nearest integer)
(h=6.626×10−34Js)