Fractional Equation(s) B

It is known that there is such a number $s$ such that if real numbers $a, b, c, d$ are all neither 0 nor 1, satisfying $a+b+c+d=s$ and $\frac{1}{a}+\frac{1}{b}+\frac{1}{c}+\frac{1}{d}=s$ , then $\frac{1}{1-a}+\frac{1}{1-b}+\frac{1}{1-c}+\frac{1}{1-d}=s$ . Find $s$ .