6. Xiaoming is playing a new type of flying chess on the computer. If the dice roll shows a black number, it means he needs to move backward; if it shows a red number, it means he needs to move forward (for example, black 2 means move back 2 steps, red 3 means move forward 3 steps). He rolled the dice 5 times, getting black 5, red 4, red 2, black 3, and red 1. After all the moves, he found himself on the 6th square. Before the first roll, he was on the $\qquad$ square
【Answer】 7

【Solution】 Restoration problem, $6-1+3-2-4+5=7$