use std::io;
use std::str::FromStr;

fn input_int_tuple() -> (i32, i32) {
    let mut line: String = String::new();
    io::stdin().read_line(&mut line);
    let vec: Vec<i32> = line.split_whitespace().map(|s| s.parse().unwrap()).collect();
    (vec[0], vec[1])
}

fn main() {
    let (n, h) = input_int_tuple();
    let mut a_vec: Vec<i32> = Vec::new();
    let mut b_vec: Vec<i32> = Vec::new();
    for i in 0..n {
        let (a, b) = input_int_tuple();
        a_vec.push(a);
        b_vec.push(b);
    }
    a_vec.sort_by(|a, b| b.cmp(a));
    let a_max = a_vec[0];
    b_vec.sort_by(|a, b| b.cmp(a));

    // println!("{:?}", a_vec);
    // println!("{:?}", b_vec);

    let mut sum = 0;
    let mut count = 0;
    for b in b_vec {
        if sum > h {
            println!("{}", count);
            return;
        }
        if b > a_max {
            sum += b;
            count += 1;
        } else {
            if (h - sum) % a_max == 0{
                println!("{}", count + (h - sum) / a_max);
            } else {
                println!("{}", count + (h - sum) / a_max + 1);
            }
            return;
        }
    }
    if sum > h {
        println!("{}", count);
        return;
    }
    if (h - sum) % a_max == 0{
        println!("{}", count + (h - sum) / a_max);
    } else {
        println!("{}", count + (h - sum) / a_max + 1);
    }
}
