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


def f(k):
    c = (k-1)//2
    if c >= n or c >= m:
        return -1
    else:
        return '0'*(n-c)+'10'*c+'1'*(m-c)


if k % 2:
    print(f(k))
else:
    if k == 0:
        if m == 0:
            print('0'*n)
        elif n == 0:
            print('1'*m)
        else:
            print(-1)
    else:
        print(f(k-1)[1:]+'0')