How many times will the marked line in the following code run when the size of the input list is n elements?

def mystery(n):
    res = 0
    if n == 0:
        return res
    else:
        i=0
        while i < n: 
            for j in range(n):
                res += j          # This line
            i+=1
    
    return res

Answer in terms of n