#pypy3の再帰速度向上
# import pypyjit
# pypyjit.set_param('max_unroll_recursion=-1')
 
#再帰回数の上限を上げる
# import sys
# sys.setrecursionlimit(10**8)
 
#両端キューの宣言
# from collections import deque
# d = deque()
 
#メモ化再帰(再帰する関数の上にデコレータを配置)
# from functools import lru_cache
# @lru_cache(maxsize = 1000000000000000000)

 
#頻出辞書用ライブラリ
# from collections import defaultdict
# di = defaultdict(int)

# コピーライブラリ
# import copy
# a = copy.copy(b)

# INF = float('inf')
# abc = "abcdefghijklmnopqrstuvwxyz"
# ABC = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"

def iinput(): return int(input())
def sinput(): return input().rstrip()
def i0input(): return int(input()) - 1
def linput(): return list(input().split())
def liinput(): return list(map(int, input().split()))
def miinput(): return map(int, input().split())
def li0input(): return list(map(lambda x: int(x) - 1, input().split()))
def mi0input(): return map(lambda x: int(x) - 1, input().split())

# Write code here.---------------------------------------------------------------------------------------

N,M,K = miinput()
if min(N,K) < K:
    print(-1)
    exit()
if N == 0:
    if K == 0:
        print("1"*M)
        exit()
    else:
        print(-1)
        exit()

ans = "0" * (N-(K-1))
n = N - (K-1)
m = M
k = K
s = "0"

for _ in range((N + M) - (N - (K-1))):
    if k == 0:
        print(-1)
        exit()
    if s == "0":
        s = "1"
    else:
        s = "0"
    ans += s
    k -= 1
print(ans)