It seems like the year of 2013 came only yesterday. Do you know a curious fact? The year of 2013 is the first year after the old 1987 with only distinct digits.

Now you are suggested to solve the following problem: given a year number, find the minimum year number which is strictly larger than the given one and has only distinct digits.
The single line contains integer *y* (1000 ≤ *y* ≤ 9000) — the year number.
def calculate_borrow_amount(k, n, w):
    total_cost = (k + k * w) * w // 2  
    borrow_amount = max(0, total_cost - n)  

    return borrow_amount

k, n, w = map(int, input().strip().split())


result = calculate_borrow_amount(k, n, w)
print(result)
