题目描述
Problem Statement
Given an integer N, find the smallest integer X that satisfies all of the conditions below.
- X is greater than or equal to N.
- There is a pair of non-negative integers (a, b) such that X=a^3+a^2b+ab^2+b^3.
Input
Input is given from Standard Input in the following format:
N
Output
Print the answer as an integer.
Constraints
- N is an integer.
- $0 \le N \le 10^{18}$
Sample Input 1
9
Sample Output 1
15
For any integer X such that $9 \le X \le 14,$ there is no (a, b) that satisfies the condition in the statement.
For X=15, (a,b)=(2,1) satisfies the condition.
Sample Input 2
0
Sample Output 2
0
N itself may satisfy the condition.
Sample Input 3
999999999989449206
Sample Output 3
1000000000000000000
Input and output may not fit into a 32-bit integer type.
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分
样例输入
9
样例输出
15