Rejection sampling

Suppose $f$ is a target probability density and $h$ is a proposal density with $f(x)\le Mh(x)$. Draw $X\sim h$ and an independent $U\sim \mathrm{Uniform}[0,1]$, and accept $X$ whenThe accepted value has density $f$, the acceptance probability is $1/M$, and the expected number of proposals is $M$.