a,b,c=map(int, input().split())
ans = ''
if c == 1:
  for i in range(a):
    ans += '0'
  ans += '1'
elif c > a + b:
  print('-1')
elif c % 2 == 0:
  print('-1')
else:
  for i in range(a-(c//2)):
    ans += '0'
  for i in range(c // 2):
    ans += '1'
    ans += '0'
  for i in range(b-(c//2)):
    ans += '1'
print(ans)