Let \( f(x)=2^{x}-x^{2},\ x\in \mathbb{R} \). If \( m \) and \( n \) are respectively the number of points at which the curves \( y=f(x) \) and \( y=f'(x) \) intersect the \( x \)-axis, then the value of \( m+n \) is __________.