题目描述

Consider the set of all reduced fractions between 0 and 1 inclusive with denominators less than or equal to N.

Here is the set when N = 5:

0/1 1/5 1/4 1/3 2/5 1/2 3/5 2/3 3/4 4/5 1/1
Write a program that, given an integer N between 1 and 160 inclusive, prints the fractions in order of increasing magnitude.

输入格式

One line with a single integer N.

输出格式

One fraction per line, sorted in order of magnitude.

样例数据

input

5

output

0/1
1/5
1/4
1/3
2/5
1/2
3/5
2/3
3/4
4/5
1/1