Changing the value in the Seed field will generate the corresponding input to the Input field.
Pressing the Download button will download the inputs for seed values seed, seed+1, ..., seed+#cases-1 at once.

By running your program locally against the generated input and pasting the output of your program into the Output field, the visualization results will be displayed.
Pressing the ▶ button starts animation.
By pressing the Save as PNG button, you can download the visualization results.

You can quickly switch between multiple outputs by pressing the Select File button at the top and selecting the directory containing the output files.
By naming the output file 1234.txt or abcd_1234.txt, the seed number (in this case 1234) is automatically set when the file is selected.

The color of each cell represents the probability of the robot being present in that cell, with cells with higher probabilities shown in red and those with lower probabilities shown in white.
Hovering the mouse cursor over each cell will display detailed information in a tooltip.
The graph on the bottom shows the number of turns on the horizontal axis and the survival rate on the vertical axis.

By checking the manual mode, you can edit the answer manually by clicking with the mouse.
Pressing the Backspace key will undo the last operation.