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)