// No.700 LOVE
package main

import (
	"fmt"
	"strings"
)

func main() {
	var n, m int
	fmt.Scan(&n, &m)

	var s string
	var isLove bool
	for i := 0; i < n; i++ {
		fmt.Scan(&s)
		if strings.Contains(s, "LOVE") {
			isLove = true
		}
	}
	if isLove {
		fmt.Println("YES")
	} else {
		fmt.Println("NO")
	}
}