A solid sphere of radius 1 cm and initial temperature of 25 °C is exposed to a gas stream at 100 °C. For the solid sphere, the density is 10⁴ kg/m³ and the specific heat capacity is 500 J/(kg K). The density of the gas is 0.6 kg/m³ and its specific heat capacity is 10³ J/(kg K). The solid sphere is approximated as a lumped system (Biot number << 1) and all specific heats are constant. If the heat transfer coefficient between the solid and gas is 50 W/(m² K), the time (in seconds) needed for the sphere to reach 95 °C is ______ (rounded off to the nearest integer).