Count the number of squares in the given figure.

The given figure consists of a \(4 \times 4\) grid, where we need to count the total number of squares of various sizes.
Step 1: Count the \( 1 \times 1 \) squares Since the grid is \(4 \times 4\), the number of \(1 \times 1\) squares is: \[ 4 \times 4 = 16. \]
Step 2: Count the \( 2 \times 2 \) squares Each \(2 \times 2\) square fits within a \(3 \times 3\) subgrid, so the count is: \[ 3 \times 3 = 9. \]
Step 3: Count the \( 3 \times 3 \) squares Each \(3 \times 3\) square fits within a \(2 \times 2\) subgrid, so the count is: \[ 2 \times 2 = 4. \]
Step 4: Count the \( 4 \times 4 \) square There is only one \(4 \times 4\) square, which is the entire grid itself: \[ 1. \]
Step 5: Compute the total number of squares \[ 16 \, (1 \times 1) + 9 \, (2 \times 2) + 4 \, (3 \times 3) + 1 \, (4 \times 4) = 30. \] Thus, the total number of squares in the grid is \(\mathbf{30}\).
Eight students (P, Q, R, S, T, U, V, and W) are playing musical chairs. The figure indicates their order of position at the start of the game. They play the game by moving forward in a circle in the clockwise direction.
After the 1st round, the 4th student behind P leaves the game.
After the 2nd round, the 5th student behind Q leaves the game.
After the 3rd round, the 3rd student behind V leaves the game.
After the 4th round, the 4th student behind U leaves the game.
Who all are left in the game after the 4th round?
