n, m, k = map(int, input().split())
if n * m == 0:
    if k:
        print(-1)
    else:
        print('0' * n if n else '1' * m)
    exit(0)
k += 1
c0 = (k + 1) // 2
c1 = k // 2
if c0 <= n and c1 <= m:
    ans = '0' * (n - c0) + '01' * c1 + '1' * (m - c1) + '0' * (k % 2)
elif c0 <= m and c1 <= n:
    assert n == c1
    ans = '10' * c1 + '1' * (m - c1)
else:
    ans = -1
print(ans)