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 mod_gcd_inv(modulus: usize, n: usize) -> (usize, usize) {
    let m = modulus as i64;
    let (g, mut x, _) = extgcd(n as i64 % m, m);
    let u = m / g;
    assert!(u > 0);
    if x < 0 {
        x += u;
    }
    assert!(0 <= x && x <= u && 1 <= g);
    (g as usize, x as usize)
}
pub fn safe_crt(
    mut m0: usize, mut r0: usize, mut m1: usize, mut r1: usize,
) -> Option<(usize, usize)> {
    use std::mem::swap;
    assert!(0 < m0 && 0 < m1);
    r0 %= m0;
    r1 %= m1;
    if m0 < m1 {
        // necessarily to avoid overflow
        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) = mod_gcd_inv(m1, m0 % m1);
    // let rd = r1.abs_diff(r0); // to avoid overflow in case r1 < r0. v1.60 <=
    let rd = if r1 < r0 { r0 - r1 } else { r1 - r0 };
    if rd % g != 0 {
        return None;
    }
    let u1 = m1 / g;
    let mut x = rd / g * inv_u0 % u1;
    // x <= m1^2. so if m0 < m1, it should be swapped at first.
    if r1 < r0 {
        x = u1 - x;
    }
    let mut r = r0 + x * m0;
    let lcm = m0 * u1;
    if r >= lcm {
        r -= lcm;
    }
    debug_assert!(r1.max(r0) <= r && r < lcm);
    Some((lcm, r))
}
pub fn crt_prod(mr: &[(usize, usize)]) -> Option<(usize, usize)> {
    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;
        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: usize = read();
            let m: usize = 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();
    }
}