Prove uniform hashing gives <=1/(1-alpha) expected unsuccessful probes

Analyze the prove uniform hashing gives <=1/(1-alpha) expected unsuccessful probes.

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

Prove uniform hashing gives <=1/(1-alpha) expected unsuccessful probes

Analyze the prove uniform hashing gives <=1/(1-alpha) expected unsuccessful probes.