Structure Of Atom

Two positively charged particles $m_1$ and $m_2$ have been accelerated across the same potential difference of 200 keV as shown below.

[Given mass of $m_1 = 1$ amu and $m_2 = 4$ amu]

The deBroglie wavelength of $m_1$ will be $x$ times of $m_2$. The value of $x$ is __________ (nearest integer)