Q31

A Young tableau is a $2D$ array of integers increasing from left to right and from top to bottom. Any unfilled entries are marked with $\infty$, and hence there cannot be any entry to the right of, or below a $\infty$. The following Young tableau consists of unique entries.

$$\begin{array}{|l|l|l|l|}\hline \textbf{1} & \text{2}& \text{5} & \text{14} \\\hline \text{3} & \text{4} & \text{6} & \text{23} \\\hline \text{10} & \text{12} & \text{18} & \text{25} \\\hline \text{31} & \text{$\infty$} & \text{$\infty$} & \text{$\infty$} \\\hline \end{array}$$

When an element is removed from a Young tableau, other elements should be moved into its place so that the resulting table is still a Young tableau (unfilled entries may be filled with a $\infty$). The minimum number of entries (other than $1$) to be shifted, to remove $1$ from the given Young tableau is _____.