Is $f(x) = 7x^7 - 4x^4 + 1$ an even function, odd function, or neither?

Enter "odd", "even", or "neither".
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
Is $f(x) = 7x^7 - 4x^4 + 1$ an even function, odd function, or neither?

Enter "odd", "even", or "neither".
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
\text{neither}
Is $f(x) = 7x^7 - 4x^4 + 1$ an even function, odd function, or neither?

Enter "odd", "even", or "neither".
train