// This is a program that is trying to use a completed version of the // `total_cost` function from the previous exercise. It's not working though! // Why not? What should we do to fix it? use std::num::ParseIntError; // Don't change this function. fn total_cost(item_quantity: &str) -> Result<i32, ParseIntError> { let processing_fee = 1; let cost_per_item = 5; let qty = item_quantity.parse::<i32>()?; Ok(qty * cost_per_item + processing_fee) } // TODO: Fix the compiler error by changing the signature and body of the // `main` function. fn main() { let mut tokens = 100; let pretend_user_input = "8"; // Don't change this line. let cost = total_cost(pretend_user_input)?; if cost > tokens { println!("You can't afford that many!"); } else { tokens -= cost; println!("You now have {tokens} tokens."); } }