import sys

n, m, k = map(int, input().split())

if k == 0:
  if n == 0:
    print("1" * m)
  elif m == 0:
    print("0" * n)
  else:
    print(-1)
  sys.exit()

if k % 2 == 1:
  if n - (k - 1) // 2 <= 0 or m - (k - 1) // 2 <= 0:
    print(-1)
  else:
    print("0" * (n - (k - 1) // 2) + "10" * ((k - 1) // 2) + "1" * (m - (k - 1) // 2))
else:
  if n - 1 - (k - 1) // 2 <= 0 or m - (k - 1) // 2 <= 0:
    if m - 1 - (k - 1) // 2 <= 0 or n - (k - 1) // 2 <= 0:
      print(-1)
    else:
      print("1" + "01" * ((k - 1) // 2) + "0" * (n - (k - 1) // 2) + "1" * (m - 1 - (k - 1) // 2))
  else:
    print("0" * (n - 1 - (k - 1) // 2) + "10" * ((k - 1) // 2) + "1" * (m - (k - 1) // 2) + "0")