program W
implicit none
integer::N
real(16)::ANS=0
integer::S(6)=(/2,3,5,7,11,13/),G(6)=(/4,6,8,9,10,12/)
integer::i,j
read*,N
do i=1,6
    do j=1,6
        if(S(i)*G(j)==N)ANS=ANS+1
    end do
end do
print"(f0.20)",ANS/36.0
end program W