After absorbing a slowly moving neutron of mass

After absorbing a slowly moving neutron of mass $\mathrm{m}_{\mathrm{N}}($ momentum $\sim 0)$ a nucleus of mass $\mathrm{M}$ breaks into two nuclei of masses $\mathrm{m}_{1}$ and $5 \mathrm{~m}_{1}\left(6 \mathrm{~m}_{1}=\mathrm{M}+\mathrm{m}_{\mathrm{N}}\right)$, respectively. If the de Broglie wavelength of the nucleus with mass $m_{1}$ is $\lambda$, then de Broglie wavelength of the other nucleus will be:-