def lscan; gets.chomp.split.map(&:to_i); end

def solve(n, m, k)
  if n == 0
    return '-1' if k > 0
    return '1'*m
  end
  if m == 0
    return '-1' if k > 0
    return '0'*n
  end
  
  # 10001 > 00110
  # 10101 k=4
  # 01010 k=4
  # 0010110 k=4
  
  if k.odd?
    c = [n,m].min
    return '-1' if c*2 < k+1
    # mid = '01'*c
    n -= c
    m -= c
    return '0'*n + '01'*c + '1'*m
  end
  
  if k.even?
    if n >= k/2+1 && m >= k/2
      # 0010110
      c = k/2
      # mid = '01'*c
      n -= c
      m -= c
      # tail = '0'
      n -= 1
      return '0'*n + '01'*c + '1'*m + '0'
    end
    
    if n >= k/2 && m >= k/2+1
      # 10-0101
      c = k/2
      # mid = '01'*c
      n -= c
      m -= c
      # head = '1'
      m -= 1
      return '1' + '0'*n + '01'*c + '1'*m
    end
  end
  
  '-1'
end



while line = gets
  puts solve(*line.chomp.split.map(&:to_i))
end