OPS = {}
OPS["*"] = ->(n1, n2){ n1 + n2 }
OPS["+"] = ->(n1, n2){ n1 * n2 }

S = gets
ss = S.split(/(?=\D)|(?<=\D)/)
while i = ss.index{|s| OPS[s]} do
  n1 = ss[i - 1].to_i
  op = ss[i]
  n2 = ss[i + 1].to_i
  ss[i - 1] = OPS[op].call(n1, n2)
  ss.delete_at(i)
  ss.delete_at(i)
end

puts ss[0]