Identify 3 common mistakes in the following sentence
The three common mistakes in the given sentence are:
1. Misspelling of the word "success" as "sucsess".
2. Lack of comma before the conjunction "and" (i.e. missing serial comma).
3. Possible ambiguity in whether working smart is a separate key to success, or if only working smart and hard together is the key to success.
He believes that the key to sucsess is working smart and hard.
Below is an instruction that describes a task, paired with an input that provides further context. Write a response that appropriately completes the request.

### Instruction:
Identify 3 common mistakes in the following sentence

### Input:
He believes that the key to sucsess is working smart and hard.

### Response:
The three common mistakes in the given sentence are:
1. Misspelling of the word "success" as "sucsess".
2. Lack of comma before the conjunction "and" (i.e. missing serial comma).
3. Possible ambiguity in whether working smart is a separate key to success, or if only working smart and hard together is the key to success.