n, m, k = map(int, input().split())

if n == m:
    if 2 * n - 1 < k:
        print(-1)
    else:
        if k % 2 == 1:
            num = (k + 1) // 2
            n -= num
            m -= num
            print('0' * n + '01' * num + '1' * m)
        else:
            num = k // 2
            n -= num
            m -= num
            print('0' * (n - 1) + '01' * num + '1' * m + '0')
else:
    min_ = min(n, m)
    if 2 * min_ < k:
        print(-1)
    else:
        if k % 2 == 1:
            num = (k + 1) // 2
            n -= num
            m -= num
            print('0' * n + '01' * num + '1' * m)
        else:
            num = k // 2
            n -= num
            m -= num
            if n >= 1:
                print('0' * (n - 1) + '01' * num + '1' * m + '0')
            else:
                print('10' * num + '1' * m)