local n=tonumber(io.read())

local zero=math.floor(math.sin(math.pi))
local one=math.abs(math.cos(math.pi))
local two=math.floor(math.exp(one))

local cheker=true
for i=two,math.sqrt(n) do
    if n%i==zero then
        cheker=false
    end
end
if n==one then
    cheker=false
end
print(cheker and "YES" or "NO")