fn main() {
    input! {
        h: i64,
        w: i64,
        x: i64,
        y: i64,
        a: i64,
        b: i64,
    }
    let mut row = (h, x, a);
    let mut col = (w, y, b);
    let mut ans = std::i64::MAX;
    for _ in 0..2 {
        let (h, x, a) = row;
        let (w, y, b) = col;
        let can = |i: i64, j: i64| -> bool {
            let free = a * i + j * b;
            let rect = (i * x).min(h) * (j * y).min(w);
            rect + free >= h * w
        };
        for i in 0..=h {
            let mut ok = h * w;
            let mut ng = -1;
            while ok - ng > 1 {
                let mid = (ok + ng) / 2;
                if can(i, mid) {
                    ok = mid;
                } else {
                    ng = mid;
                }
            }
            if can(i, ok) {
                ans = ans.min(i + ok);
            }
        }
        std::mem::swap(&mut row, &mut col);
    }
    println!("{}", ans);
}

// ---------- begin input macro ----------
// reference: https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8
#[macro_export]
macro_rules! input {
    (source = $s:expr, $($r:tt)*) => {
        let mut iter = $s.split_whitespace();
        input_inner!{iter, $($r)*}
    };
    ($($r:tt)*) => {
        let s = {
            use std::io::Read;
            let mut s = String::new();
            std::io::stdin().read_to_string(&mut s).unwrap();
            s
        };
        let mut iter = s.split_whitespace();
        input_inner!{iter, $($r)*}
    };
}

#[macro_export]
macro_rules! input_inner {
    ($iter:expr) => {};
    ($iter:expr, ) => {};
    ($iter:expr, $var:ident : $t:tt $($r:tt)*) => {
        let $var = read_value!($iter, $t);
        input_inner!{$iter $($r)*}
    };
}

#[macro_export]
macro_rules! read_value {
    ($iter:expr, ( $($t:tt),* )) => {
        ( $(read_value!($iter, $t)),* )
    };
    ($iter:expr, [ $t:tt ; $len:expr ]) => {
        (0..$len).map(|_| read_value!($iter, $t)).collect::<Vec<_>>()
    };
    ($iter:expr, chars) => {
        read_value!($iter, String).chars().collect::<Vec<char>>()
    };
    ($iter:expr, bytes) => {
        read_value!($iter, String).bytes().collect::<Vec<u8>>()
    };
    ($iter:expr, usize1) => {
        read_value!($iter, usize) - 1
    };
    ($iter:expr, $t:ty) => {
        $iter.next().unwrap().parse::<$t>().expect("Parse error")
    };
}
// ---------- end input macro ----------