/* 
 *     Author:  srtry
 *     Created: 2026-01-10T00:03:43+09:00
 *     Coding:  utf-8-unix
 */

use proconio::input;
use std::io::{stdout,Write,BufWriter};
use std::mem::swap;

fn main() {
    input!{
        mut x1:usize, mut y1:usize,
        mut x2:usize, mut y2:usize,
        mut x3:usize, mut y3:usize,
    }

    let out = stdout();
    let mut out = BufWriter::new(out.lock());
    
    if y1>=y2 {swap( &mut y1, &mut y2); swap( &mut x1, &mut x2);};
    if y1>=y3 {swap( &mut y1, &mut y3); swap( &mut x1, &mut x3);};
    if y2>=y3 {swap( &mut y2, &mut y3); swap( &mut x2, &mut x3);};

    let lcm:usize = {
        let mut a:usize = y3.clone();
        let mut b:usize = y2.clone();
        let mut tmp:usize;
        loop {
            if a%b == 0 {break;}
            tmp = a;
            a = b.clone();
            b = tmp%a;
        }
        y2*y3/b
    };

    let mut flg:bool = true;
    
    let mut p:usize = if x3!=0 {x3} else {y3};
    for _ in 0..y2 {
        if p%y2 == x2 {
            flg = false;
            break;
        }
        p += y3;
    }
    if flg {
        write!(out, "-1", ).unwrap();
        return;
    }

    flg = true;
    let mut ans:usize = p;
    for _ in 0..y1 {
        if ans%y1 == x1 {
            flg = false;
            break;
        }
        ans += lcm;
    }
    if flg {
        write!(out, "-1").unwrap();
        return
    }

    write!(out, "{}", ans).unwrap();
}