Find all functions f:R→Rf: \mathbb{R} \to \mathbb{R}f:R→R such that yf(x+1)=f(x+y−f(x))+f(x)f(f(y))yf(x + 1) = f(x + y - f(x)) + f(x)f(f(y))yf(x+1)=f(x+y−f(x))+f(x)f(f(y)) for all x,y∈Rx, y \in \mathbb{R}x,y∈R.