B. Rudolf and 121

Rudolf has an array 𝑎 of 𝑛 integers, the elements are numbered from 1 to 𝑛.

In one operation, he can choose an index 𝑖 (2≤𝑖≤𝑛−1) and assign:

• 𝑎𝑖−1=𝑎𝑖−1
• 𝑎𝑖=𝑎𝑖−2
• 𝑎𝑖+1=𝑎𝑖+1−1

Rudolf can apply this operation any number of times. Any index 𝑖can be used zero or more times.

Can he make all the elements of the array equal to zero using this operation?