Giải bài trực tuyến

Given a, b, c, d, find a fraction p/q with minimum q, and satisfied a/b < p/q < c/d.

Input

For each test case, one line contains four integers a, b, c, d.

Output

For each test case, print the fraction(see the sample for details).If multiple solution exists, output the one with minimum p.

Example

Input:
1 3 1 2
2 1 3 1
2 1 4 1
1000 1001 1001 1002

Output:
2/5
5/2
3/1
2001/2003

Constraints

Dataset 1: a, b, c, d (1 <= a, b, c, d <= 1e9, and a/b < c/d)