use std::{collections::BinaryHeap, cmp::Reverse};


const INF: u32 = (1u32 << 30) - 1;
const OFFSET: usize = 30000001;

fn main() {
    let mut t = String::new();
    std::io::stdin().read_line(&mut t).ok();
    let t: isize = t.trim().parse().unwrap();
    let mut xa = String::new();
    std::io::stdin().read_line(&mut xa).ok();
    let xa: Vec<usize> = xa.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();
    let x = xa[0] as u32;
    let a = xa[1];
    let mut yb = String::new();
    std::io::stdin().read_line(&mut yb).ok();
    let yb: Vec<usize> = yb.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();
    let y = yb[0] as u32;
    let b = yb[1];

    let t = (t + OFFSET as isize) as usize;
    let goal = t as usize;
    let mut checked = vec![INF; OFFSET*2+1];
    checked[OFFSET] = 0;
    let mut pque = BinaryHeap::new();
    pque.push((Reverse(0u32), OFFSET));
    while let Some((Reverse(cost), pos)) = pque.pop() {
        if checked[pos] < cost { continue; }
        if pos+1 < checked.len() && checked[pos+1] > cost + 1 {
            pque.push((Reverse(cost+1), pos+1));
            checked[pos+1] = cost+1;
        }
        if pos+a < checked.len() && checked[pos+a] > cost + x {
            pque.push((Reverse(cost+x), pos+a));
            checked[pos+a] = cost+x;
        }
        if pos >= b && checked[pos-b] > cost + y {
            pque.push((Reverse(cost+y), pos-b));
            checked[pos-b] = cost+y;
        }
    }
    println!("{}", checked[goal]);
}