An insulated beaker with negligible mass contains liquid water with a mass of 0.205kg and a temerature of 67.1 degree C. How much ice at a temperature of -14 degrre C must be drop into the water so that the final temperature of the system will be 21.0 degree C ? (Take the specific heat of liquid water to be 41900 J/kg.K, the specific heat of ice to be 2100 J/kg.K, and the heat of fusion water to be 334 KJ/kg)