On a frictionless horizontal plane, a bob of mass m=0.1 kg is attached to a spring with natural length l₀=0.1 m. The spring constant is k₁=0.009 N m⁻¹ when l>l₀ and k₂=0.016 N m⁻¹ when l<l₀. Initially the bob is released from l=0.15 m. Assume that Hooke’s law remains valid throughout the motion. If the time period of the full oscillation is T=(nπ) s, then the integer closest to n is ____.