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 or splits > n1:
            return -1
        ans = '0' * (n0 - splits) + '10' * splits + '1' * (n1 - splits)
        if sum(ans[i] != ans[i+1] for i in range(len(ans) - 1)) == diffs:
            return ans
        return -1
    if n0 >= n1:
        ans = solve(n0-1, n1, diffs-1)
        if ans == -1: return -1
        ans = ans + '0'
        return ans
    if diffs > 2 * n0: return -1
    if diffs == 2 * n0:
        return '10' * n0 + '1' * (n1 - n0)
    n0 -= 1
    if n0 < 0: return -1
    splits = diffs // 2
    return '0' * (n0 - splits) + '01' * splits + '1' * (n1 - splits) + '0'



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