Problem Description

You are given four positive integers $a,\,b,\,c,\,d$. Find a fraction $\frac{p}{q}$ in lowest terms such that $\frac{a}{b} < \frac{p}{q} < \frac{c}{d}$.

If there are multiple solutions, output the one with the smallest $q$. If there are still multiple solutions, output the one with the smallest $p$.

Input Format

This problem contains multiple test cases. There are several lines, and each line contains four positive integers, which are $a,b,c,d$ for one test case.

Output Format

For each test case, output one line. If the answer is $\frac{p}{q}$, print it in the format p/q.

1 3 1 2
2 1 3 1
2 1 4 1
1000 1001 1001 1002

2/5
5/2
3/1
2001/2003

Hint

The testdata guarantees that there exists at least one fraction in lowest terms that satisfies the condition.

Translated by ChatGPT 5