#include<stdio.h>
#include<string.h>

int main(void){
    int n, m, i;
    char s[50][51];
    m = 0;
    scanf("%d%d", &n, &m);
    for(i=0;i<n;i++){
        scanf("%s",s[i]);
        if(strstr(s[i],"LOVE") != NULL) m+=1;
    }
    if(m>0) printf("YES");
    else printf("NO");
    return 0;
}