백준 #25304번 영수증

import java.util.Scanner;
public class Main {
	public static void main(String[] args) {
		
		Scanner sc = new Scanner(System.in);
		
		long x = sc.nextLong();
		int n = sc.nextInt();
		long total = 0;
		
		for(int i = 0; i < n; i++) {
			int a = sc.nextInt();
			int b = sc.nextInt();
			total += a * b;
		}
		
		if(x == total) {
			System.out.println("Yes");
		}else {
			System.out.println("No");
		}
		sc.close();
	}
}