# 1852. Ordered Fractions

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

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


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2.3 EMB 奖励。