import java.io.IOException;
import java.io.InputStream;
import java.util.Arrays;
import java.util.NoSuchElementException;
import java.util.PriorityQueue;

public class Main {

	public static void main(String[] args) {
		new Main().run();
	}
	
	boolean check(int[] t, int T, int num) {
		int n=t.length;
		PriorityQueue<Integer> in=new PriorityQueue<>();
		for (int i=0;i<num;++i) in.add(0);
		int p=n-1;
		while (p>=0) {
			int time=in.poll();
			if (t[p]+time > T) {
				return false;
			} else {
				--p;
				if (p >= 0) in.add(t[p]+time);
			}
		}
		return true;
	}
	
	void run() {
		FastScanner sc=new FastScanner();
		int T=sc.nextInt();
		int N=sc.nextInt();
		int[] t=new int[N];
		for (int i=0;i<N;++i) t[i]=sc.nextInt();
		int ok=N;
		int ng=0;
		while(ok-ng>1) {
			int middle=(ok+ng)/2;
			if (check(t,T,middle)) {
				ok=middle;
			} else {
				ng=middle;
			}
		}
		System.out.println(ok);
	}
	
	void tr(Object...objects) {System.out.println(Arrays.deepToString(objects));}
}

class FastScanner {
    private final InputStream in = System.in;
    private final byte[] buffer = new byte[1024];
    private int ptr = 0;
    private int buflen = 0;
    private boolean hasNextByte() {
        if (ptr < buflen) {
            return true;
        }else{
            ptr = 0;
            try {
                buflen = in.read(buffer);
            } catch (IOException e) {
                e.printStackTrace();
            }
            if (buflen <= 0) {
                return false;
            }
        }
        return true;
    }
    private int readByte() { if (hasNextByte()) return buffer[ptr++]; else return -1;}
    private static boolean isPrintableChar(int c) { return 33 <= c && c <= 126;}
    public boolean hasNext() { while(hasNextByte() && !isPrintableChar(buffer[ptr])) ptr++; return hasNextByte();}
    public String next() {
        if (!hasNext()) throw new NoSuchElementException();
        StringBuilder sb = new StringBuilder();
        int b = readByte();
        while(isPrintableChar(b)) {
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    }
    public long nextLong() {
        if (!hasNext()) throw new NoSuchElementException();
        long n = 0;
        boolean minus = false;
        int b = readByte();
        if (b == '-') {
            minus = true;
            b = readByte();
        }
        if (b < '0' || '9' < b) {
            throw new NumberFormatException();
        }
        while(true){
            if ('0' <= b && b <= '9') {
                n *= 10;
                n += b - '0';
            }else if(b == -1 || !isPrintableChar(b)){
                return minus ? -n : n;
            }else{
                throw new NumberFormatException();
            }
            b = readByte();
        }
    }
    public int nextInt() {
        long nl = nextLong();
        if (nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE) throw new NumberFormatException();
        return (int) nl;
    }
    
    public double nextDouble() { return Double.parseDouble(next());}
}