A superheterodyne receiver operates in the frequency range of $58$ MHz – $68$ MHz. The intermediate frequency $f_{IF}$ and local oscillator frequency $f_{LO}$ are chosen such that $f_{IF} \leq f_{LO}$. It is required that the image frequencies fall outside the $58$ MHz – $68$ MHz band. The minimum required $f_{IF}$ (in MHz) is _________