1. On the table, there are sticks of lengths $1,2,3, \ldots, n$ centimeters. It is known that from them, 40 triangles can be formed, using each stick no more than once, but 41 cannot. Find $n$ (the length of the longest stick)? If there are multiple possible answers, list them in ascending order separated by a semicolon.
Answer: $121 ; 122 ; 123 \mid 121,122,123$