Finite sequence length before and after removing repetitions

Question

I have a sequence $S$ of length $n^3+1$ where the elements are not necessarily distinct and every element appears at most $n$ times. Why does the sequence $S'$ where I remove all repetitions from $S$ have at least $n^2+1$ elements?

Answer 1

Hint: If the length of sequence $S$ were $n^3$ and all terms were repeated exactly $n$ times, then you would have exactly $n^2$ distinct terms.