시간 제한 메모리 제한 제출 정답 맞은 사람 정답 비율
2 초 512 MB 8 5 3 60.000%

문제

A positive integer k is called a jimp number if there is exactly one triple of positive integers (a, b, c) such that a, b, and c are consecutive terms of an arithmetic progression (exactly in that order) and a2 + b2 + k = c2.

Count the jimp numbers which are not greater than the given number n.

입력

The only line contains a single integer n (1 ≤ n ≤ 1011).

출력

Print a single integer: the answer to the problem.

예제 입력 1

5

예제 출력 1

2

예제 입력 2

100

예제 출력 2

25