package main

import (
	"fmt"
	"strings"
)

func main() {
	var n, m int
	fmt.Scan(&n, &m)
	var s string
	for i := 0; i < n; i++ {
		fmt.Scan(&s)
		if strings.Index(s, "LOVE") >= 0 {
			fmt.Println("YES")
			return
		}
	}
	fmt.Println("NO")
}