Find the Differential equation $y=\sum_{i=1}^3 c_i e^{m_ix}$

Find the Differential equation $y=\sum_{i=1}^3 c_i e^{m_ix}$

Finding the differential equation corresponding to $$y=\sum_{i=1}^3 c_i
e^{m_ix}$$ where $c_i$ are the arbitrary constants and $m_1,m_2,m_3$ are
the roots of the equation $m^3-7m-1=0$