Sign test p-value from the observed tail

Let $X_1,X_2,…,X_n$ be a random sample of size $n$ ($\ge 11$) from a population with continuous and strictly increasing cumulative distribution function $F(\cdot)$ with an unknown median $M$. To test $H_0: M = 10$ against $H_1: M > 10$ at level $\alpha$, let the statistic $T$ denote the number of observations larger than 10. Let $t_0$ be the observed value of the test statistic $T$. Consider the test which rejects $H_0$ if $T \ge c$. Then the $p$-value of the test is