# Program to Find sum of series 1+(1+3)+(1+3+5)+....+N 

print("Enter the range of number(Limit):")
n = int(input())
i = 1
sum = 0
while (i <= n):
    for j in range(1, i + 1,2):
        sum+=j
    i += 2
print("The sum of the series = ", sum)