S.H.M. question on spring block question

i have a shm question, which i have seen on a magazine

a spring is attached to a ceiling and spring is connected to a pulley now one end of string passing through pulley is conneted with a spring and this spring is attached to ground and other end of string passing through pulley is connected with a block of mass m, spring constant of both springs are k, we have to find out time period of shm of block