Prove the Singleton bound: A(n, d) ≤ 2^(n−d+1).

Analyze the prove the singleton bound: a(n, d) ≤ 2^(n−d+1)..

Examples
Input: "test_input_1"
Output: "output_1"
Hints

Prove the Singleton bound: A(n, d) ≤ 2^(n−d+1).

Analyze the prove the singleton bound: a(n, d) ≤ 2^(n−d+1)..