2.1.2 Ordered Fractions

/*
ID: awsd1231
PROG: frac1 
LANG: C++
*/
#include<iostream>
#include<cstdio>
#include<algorithm>
using namespace std;
struct T {
	int a[3];
	double v;
//	T() {a[1] = ‘/‘;}
}ans[13000];
int n;
int gcd(int a, int b) {
	if (a < b) {
		int t = a; a = b; b = t;
	}
	if (b) return gcd(b, a % b);
	return a;
}
bool operator < (T a, T b) {
	return a.v < b.v;
}
int main () {
	freopen("frac1.in", "r", stdin);
	freopen("frac1.out", "w", stdout);
	scanf("%d", &n);
	ans[0].v = 1;
	ans[0].a[0] = 1;
	ans[0].a[2] = 1;
	ans[1].v = 0;
	ans[1].a[0] = 0;
	ans[1].a[2] = 1;
	int idx = 2;
	for (double i = 1; i != n + 1; ++i) {
		for (double j = 1; j != i; ++j) {
			if(!i % 2 && !j % 2) continue;
			if(gcd(j, i) == 1) {
				ans[idx].v = j/i;
				ans[idx].a[0] = j;
				ans[idx++].a[2] = i;
			}
		}
	}
	sort(ans, ans + idx);
	for(int i = 0; i != idx; ++i) {
		printf("%d/%d\n", ans[i].a[0], ans[i].a[2]);
	}
	return 0;
}