16.1. Calculate: $2^{15}-2^{14}-2^{13}-\ldots-2^{1}-1$.

$$
\text { (6-7 grades) }
$$
16.1. Noticing that $2^{15}-2^{14}=2 \cdot 2^{14}-2^{14}=2^{14}$, we will reduce the given expression to the following:

$$
2^{14}-2^{13}-2^{12}-\ldots-2-1
$$

Continuing to proceed in this manner further and further, we will find that the desired sum is 1.