use std::io::*;
//use std::num;
use std::str::FromStr;
//use std::time::Instant;

fn main() {
    //let now = Instant::now();
    let n: u64 = read();
    let m: usize = read();
    let mut a = vec![0; m];
    let mut count: u64 = 0;
    let mut tmp;

    for _i in 0..a.len(){
        a[_i] = read();
    }

    for _j in 0..a.len()-1{
        for _i in 0..a.len()-1{
            if a[_i] > a[_i + 1]{
                tmp = a[_i];
                a[_i] = a[_i + 1];
                a[_i + 1] = tmp;
            }
        }
    }

    /*
    for _i in 0..a.len(){
        println!("{}",a[_i]);
    }
    */
    
    for _i in 0..=a.len(){
        if count == n{
            println!("{}",_i);
            break;
        }else if count >= n{
            println!("{}",_i);
            break;
        }
        count += a[_i];
    }

    //println!("[DEBUG_PRINT] {} ms", now.elapsed().as_millis());
}

pub fn min(x: usize, y: usize) -> usize {
    let z: usize;

    if x <= y {
        z = x;
    } else {
        z = y;
    }

    return z;
}

pub fn read<T: FromStr>() -> T {
    let stdin = stdin();
    let stdin = stdin.lock();
    let token: String = stdin
        .bytes()
        .map(|c| c.expect("failed to read char") as char)
        .skip_while(|c| c.is_whitespace())
        .take_while(|c| !c.is_whitespace())
        .collect();
    token.parse().ok().expect("failed to parse token")
}

pub fn read_array() -> Vec<char> {
    let array: String = read();
    let chars: Vec<char> = array.trim().chars().collect::<Vec<char>>();
    chars
}

pub fn get_data() -> Vec<u64> {
    let mut s: String = String::new();
    std::io::stdin().read_line(&mut s).ok();
    let vec: Vec<u64> = s
        .trim()
        .split_whitespace()
        .map(|e| e.parse().ok().unwrap())
        .collect();

    vec
}

pub fn get_chars() -> Vec<char> {
    let mut s: String = String::new();
    std::io::stdin().read_line(&mut s).ok();

    let vec: Vec<char> = s.trim().chars().collect::<Vec<char>>();

    vec
}