There's multiple ways to approach it... but the key is that you want to do something (add a "1" to a string) an (input) number of times. You then want to add a line break to move to the next line. And then you want to do the same thing again, and again, for a total of (again, input) number of times.
one one one one line break one one one one line break one one one one line break one one one one (unclear if they want a line break at the end or not).
The obvious way is to use for loop(s). A for loop is a control flow that allows you to run some instructions multiple times.