Statistics and Probability: JEE Main 2024 Mathematics question

Let $\mathrm{a}, \mathrm{b}, \mathrm{c} \in \mathbf{N}$ and $\mathrm{a}< \mathrm{b}< \mathrm{c}$. Let the mean, the mean deviation about the mean and the variance of the 5 observations $9,25, a, b, c$ be 18, 4 and $\frac{136}{5}$, respectively. Then $2 a+b-c$ is equal to ________