// No.1205 Eye Drops
package main

import (
	"fmt"
	"sort"
)

func main() {
	var n, m int
	fmt.Scan(&n, &m)
	type C struct {
		T int // time
		P int // position
	}
	mm := make([]C, m)
	for i := 0; i < m; i++ {
		fmt.Scan(&mm[i].T, &mm[i].P)
	}
	sort.Slice(mm, func(i, j int) bool {
		return mm[i].T < mm[j].T
	})
	prev := C{T: 0, P: 0}
	ans := "Yes"
	for j := 0; j < m; j++ {
		t := mm[j].T - prev.T
		p := max(prev.P-mm[j].P, mm[j].P-prev.P) - t
		if p > 0 {
			ans = "No"
			break
		}
		prev.P = mm[j].P
		prev.T = mm[j].T
	}
	fmt.Println(ans)
}