In a particular system of units, a physical quantity can be expressed in terms of the electric charge e, electron mass mₑ, Planck’s constant h, and Coulomb’s constant k=1/(4πε₀), where ε₀ is the permittivity of vacuum. In terms of these physical constants, the dimension of the magnetic field is [B]=[e]^α[mₑ]^β[h]^γ[k]^δ. The value of α+β+γ+δ is ____.