Harvard’s Faculty of Arts of Sciences will reduce its budget by 19 percent, or $220 million, over the next two years. The dean, Michael Smith, said in a talk with faculty and staff Tuesday that six groups of professors, staff and students would be formed to identify areas in which to make the cuts. The cost-saving measures are a response to the projection that Harvard’s endowment, the largest in higher education, will fall 30 percent this year. The Faculty of Arts and Sciences has already cut $4 million from this year’s budget and $73 million from next year’s. Smith said the working groups have to find another $143 million in cuts to balance the budget in the following year.