import sys
#sys.setrecursionlimit(500000)
def I(): return int(sys.stdin.readline().rstrip())
def MI(): return map(int,sys.stdin.readline().rstrip().split())
def TI(): return tuple(map(int,sys.stdin.readline().rstrip().split()))
def LI(): return list(map(int,sys.stdin.readline().rstrip().split()))
def SI(): return sys.stdin.readline().rstrip()
def LS(): return list(sys.stdin.readline().rstrip())
#for i, pi in enumerate(p):
from collections import defaultdict,deque
import bisect
import itertools
dic = defaultdict(int)
d = deque()
YN = ['No','Yes']
N,M,K = LI()

if K % 2:
  s = (K+1) // 2
  if N < s or M < s:
    print(-1)
    exit()
  print('0'*(N-s)+'01'*(s)+'1'*(M-s))
else:
  N -= 1
  K -= 1
  s = (K+1) // 2
  if N < s or M < s:
    N += 1
    
    M -= 1
    if N < s or M < s:
      print(-1)

      exit()
    print('1'+'0'*(N-s)+'01'*(s)+'1'*(M-s))
    exit()
  print('0'*(N-s)+'01'*(s)+'1'*(M-s)+'0')