program ABC065A
    implicit none
    integer(8)::A,B,X
    read(5,*)X,A,B

    if(B-A<=0)then
        print'(A)',"delicious"
    else if(B-A<=X)then
        print'(A)',"safe"
    else
        print'(A)',"dangerous"
    end if
end program ABC065A