A massless rod of length $l$ is hung from the ceiling with the help of two identical wires attached at its ends. A block is hung on the case, the frequency of the $1^{\mathrm{st}}$ harmonic of the wire on the left end is equal to the frequency of the $2^{\mathrm{nd}}$ harmonic of the wire on the right. The value of $\mathrm{X}$ is