use std::io;
use std::str::FromStr;
use std::cmp::{ min, max };
use std::collections::{ BinaryHeap, VecDeque };

fn gcd(a:i32,b:i32) -> i32 { if b == 0 { a } else { gcd(b, a%b) } }
fn lcd(a:i32,b:i32) -> i32 { a / gcd(a, b) * b }

fn main() {
    let mut sc = Scanner::new();
    let a: i32 = sc.cin();
    let b: i32 = sc.cin();
    let c: i32 = sc.cin();
    let m = lcd(lcd(a, b), c);
    // println!("m={}", m);
    // println!("{} {} {}", m/a, m/b, m/c);
    let n = gcd(m/a-m/b, m/b-m/c);
    // println!("n={}", n);
    {
        let k = gcd(m, n);
        println!("{}/{}", m/k, n/k);
    }
}

#[allow(dead_code)]
struct Scanner { stdin: io::Stdin, buffer: VecDeque<String>, }
#[allow(dead_code)]
impl Scanner {
    fn new() -> Scanner { Scanner { stdin: io::stdin(), buffer: VecDeque::new() } }
    fn reserve(&mut self) {
        while self.buffer.len() == 0 {
            let mut line = String::new();
            let _ = self.stdin.read_line(&mut line);
            for w in line.split_whitespace() {
                self.buffer.push_back(String::from(w));
            }
        }
    }
    fn cin<T: FromStr>(&mut self) -> T {
        self.reserve();
        match self.buffer.pop_front().unwrap().parse::<T>() {
            Ok(a) => a,
            Err(_) => panic!("parse err")
        }
    }
    fn get_char(&mut self) -> char {
        self.reserve();
        let head = self.buffer[0].chars().nth(0).unwrap();
        let tail = String::from( &self.buffer[0][1..] );
        if tail.len()>0 { self.buffer[0]=tail } else { self.buffer.pop_front(); }
        head
    }
}