while n = STDIN.gets
  n = n.split(/ /)
  for i in 0.. 2
    n[i] = n[i].to_i
  end
  o = (n[0]*1.0/n[1]).to_s
  a = 0
  if n[2] != 0
    for i in o.index(".")+1.. o.index(".")+n[2]
      if o[i] != nil
        a+=o[i].to_i
      end
    end
  end
  puts a
end