N, Q = gets.split.map(&:to_i)
A = gets.split.map(&:to_i)
S = Q.times.map { gets.to_i }

B = []
C = []

A.each do |a|
  if C.empty?
    C << a
  else
    C << C.last + a
  end

  if B.empty?
    B << a * (1 + a) / 2
  else
    B << B.last + a * (1 + a) / 2
  end
end

def f(s)
  return -1 if B[-1] < s
  return 0 if B[0] >= s

  ok = N - 1
  ng = 0

  while (ok - ng).abs >= 2
    x = (ok + ng) / 2

    if B[x] >= s
      ok = x
    else
      ng = x
    end
  end

  ok
end

def g(s, a, offset = 0)
  return 1 if offset + 1 >= s

  ng = 1
  ok = a

  while (ok - ng).abs >= 2
    x = (ok + ng) / 2
    b = offset + x * (1 + x) / 2

    if b >= s
      ok = x
    else
      ng = x
    end
  end

  ok
end

S.each do |s|
  idx = f(s)

  if idx == -1
    puts -1
  else
    res = if idx == 0
            g(s, A[0])
          else
            g(s, A[idx], B[idx - 1])
          end

    if idx == 0
      puts res
    else
      puts C[idx - 1] + res
    end
  end
end