# More fun with quadratic forms

**Algebra**Level 5

Find the smallest positive integer \(n\) such that there exist real numbers \(x_0,x_1,\ldots,x_n\) with \(\displaystyle \sum_{k=0}^{n}x_k^2=1\) and \(\displaystyle \sum_{k=1}^{n}x_0x_k>1\).

If you come to the conclusion that no such \(n\) exists, enter 666.