def sum_Even(l,r):
    def sum_Natural(n): 
        sum = (n * (n + 1)) 
        return int(sum) 
     
    return (sum_Natural(int(r / 2)) - sum_Natural(int((l - 1) / 2))) 
def sum_Even(l, r):
    def sum_Natural(n2):
        sum = n2 * (n2 + 1)
       
        return int(sum)
    return sum_Natural(int(r / 2)) - sum_Natural(int((l - 1) / 2))