def solve(n0, n1, diffs):
    if diffs == 0:
        if n0 == 0:
            return '1' * n1
        if n1 == 0:
            return '0' * n0
        return -1
    if diffs >= n0 + n1:
        return -1
    if diffs & 1:
        splits = diffs // 2
        if splits > n0:
            return -1
        return '0' * (n0 - splits) + '10' * splits + '1' * (n1 - splits)
    n0 -= 1
    if n0 < 0: return -1
    return solve(n0, n1, diffs - 1) + '0'

print(solve(*map(int, input().split())))