A mass $m$ is attached to two springs as shown in figure. The spring constants of two springs are $K_1$ and $K_2$. For the frictionless surface, the time period of oscillation of mass $m$ is\\
(1) $2\pi\sqrt{\frac{m}{K_1 + K_2}}$\\
(2) $\frac{1}{2\pi}\sqrt{\frac{K_1 - K_2}{m}}$\\
(3) $2\pi\sqrt{\frac{m}{K_1 - K_2}}$\\
(4) $\frac{1}{2\pi}\sqrt{\frac{K_1 + K_2}{m}}$