# Cause we're young and we're reckless

**Logic**Level 3

\[ 2^0 \, \square \, 2^1 \, \square \, 2^2 \, \square \, \ldots \, \square \, 2^n = 1991 \]

For positive integer \(n\), there are \(2^n\) ways in which we can fill the squares with \(+, - \). To make the equation true, how many of these squares are addition signs?