///, 23 bytes
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Since there is no other way to take input in ///, it is hard coded. Also, since /// is a string-based language, input is in unary.
Example with input 5:
How it works (with example input 5):
/i/00000//0./.1//1/i,//.//i. Program with input.
/i/00000/ Replace i with input. This is to make 1 uniform input.
/0./.1/ Replace "0." with ".1". This turns all the 0s to 1s in the later i without bothering the next piece of code.
/1/i,/ Replace 1s with input and a comma. This places the input into where the 1s were, essentially replacing each unary char of the input with the input, delimited with commas.
/.// Remove the period.
i. Input with period, main thing being modified by code.