I was going through this paper. On Page 6, it's written
Corollary 2.3. For any positive integers $a_1$, $a_2$, $\ldots$, $a_n$, there exist integers $x_1$, $x_2$, $\ldots$, $x_n$, such that $$a_1x_1+a_2x_2+\cdots+a_nx_n = gcd(a_1, a_2, \ldots, a_n)$$
So, I was wondering if it is true for all $n≥0$ i.e. is it universal, or are there any constraints?