use std::collections::*;

fn read<T: std::str::FromStr>() -> T {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).ok();
    s.trim().parse().ok().unwrap()
}

fn read_vec<T: std::str::FromStr>() -> Vec<T> {
    read::<String>()
        .split_whitespace()
        .map(|e| e.parse().ok().unwrap())
        .collect()
}

fn main() {
    let v: Vec<usize> = read_vec();
    let (n, h) = (v[0], v[1]);
    let mut a = vec![0; n];
    let mut b = vec![0; n];
    for i in  0..n {
        let v: Vec<i64> = read_vec();
        a[i] = v[0];
        b[i] = v[1];
    }

    let a_max = *a.iter().max().unwrap();
    let mut strong_bs = Vec::new();
    for b_num in b {
        if b_num > a_max {
            strong_bs.push(b_num);
        }
    }
    strong_bs.sort();
    strong_bs.reverse();

    let mut ans = 0;
    let mut h = h as i64;
    for b in strong_bs {
        ans += 1;
        h -= b;
        if h < 0 {
            println!("{:?}", ans);
            return;
        }
    }
    if h % a_max == 0 {
        ans += h / a_max;
    } else {
        ans += h / a_max + 1;
    }
    println!("{:?}", ans);
}
