pub fn read<T: std::str::FromStr>() -> T {
    use std::io::Read;
    std::io::stdin()
        .lock()
        .by_ref()
        .bytes()
        .map(|c| c.unwrap() as char)
        .skip_while(|c| c.is_whitespace())
        .take_while(|c| !c.is_whitespace())
        .collect::<String>()
        .parse::<T>()
        .ok()
        .unwrap()
}
pub fn extgcd(a: i64, b: i64) -> (i64, i64, i64) {
    if b == 0 {
        return if a < 0 { (-a, -1, 0) } else { (a, 1, 0) };
    }
    let (g, s, t) = extgcd(b, a % b);
    (g, t, s - a / b * t)
}
pub fn safe_crt(
    mut m0: i64, mut r0: i64, mut m1: i64, mut r1: i64,
) -> Option<(i64, i64)> {
    use std::mem::swap;
    assert!(0 < m0 && 0 < m1);
    r0 %= m0;
    r1 %= m1;
    if m0 < m1 {
        swap(&mut r0, &mut r1);
        swap(&mut m0, &mut m1);
    }
    if m0 % m1 == 0 {
        return if r0 % m1 == r1 { Some((m0, r0)) } else { None };
    }
    let (g, inv_u0, _) = extgcd(m0, m1);
    if (r1 - r0) % g != 0 {
        return None;
    }
    let u1 = m1 / g;
    let x = (r1 - r0) / g * inv_u0 % u1;
    let mut r = r0 + x * m0;
    let lcm = m0 * u1;
    if r < 0 {
        r += lcm;
    }
    debug_assert!(r1 <= r && r < lcm);
    Some((lcm, r))
}
pub fn crt_prod(mr: &[(i64, i64)]) -> Option<(i64, i64)> {
    let (mut m0, mut r0) = (1, 0);
    for &(m1, r1) in mr.iter() {
        let (lcm, ans) = safe_crt(m0, r0, m1, r1)?;
        m0 = lcm;
        r0 = ans;
        debug_assert!(r0 < m0);
    }
    Some((m0, r0))
}
pub fn main() {
    use std::io::Write;
    let out = std::io::stdout();
    let writer = &mut std::io::BufWriter::new(out.lock());
    let mr: Vec<_> = (0..3)
        .map(|_| {
            let r: i64 = read();
            let m: i64 = read();
            (m, r)
        })
        .collect();
    if let Some((m, mut r)) = crt_prod(&mr) {
        if r == 0 {
            r += m;
        }
        writeln!(writer, "{}", r).unwrap();
    } else {
        writeln!(writer, "{}", -1).unwrap();
    }
}