In a particular system of units, a physical quantity can be expressed in terms of the electric charge $e$, electron mass $m_e$, Planck's constant $h$, and Coulomb's constant $k=\frac{1}{4 \pi \varepsilon_0}$, where $\varepsilon_0$ is the permittivity of vacuum. In terms of these physical constants, the dimension of the magnetic field is $[B]=[e]^\alpha\left[m_e\right]^\beta[h]^7[k]^5$. The value of $\alpha+\beta+\gamma+\delta$ is $\_\_\_\_$