import sys
input = sys.stdin.readline
from collections import *

def g(x):
    l = [x]
    
    for _ in range(K):
        l.append(l[-1]^1)
    
    return l

N, M, K = map(int, input().split())
l0, l1 = g(0), g(1)

if l0.count(0)<=N and l0.count(1)<=M:
    l = l0
elif l1.count(0)<=N and l1.count(1)<=M:
    l = l1
else:
    exit(print(-1))

idx1, idx2 = -1, -1

for i in range(len(l)):
    if l[i]==0:
        if idx1==-1:
            idx1 = i
    else:
        idx2 = i

ans = []

for i in range(len(l)):
    ans.append(l[i])
    
    if i==idx1:
        ans += [0]*(N-l.count(0))
    elif i==idx2:
        ans += [1]*(M-l.count(1))

ans = ''.join(map(str, ans))
print(ans)