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

int main(void){
  int i, j;
  int n, m;
  char s[51], s1[5];
  int flag = 0;
  scanf("%d %d", &n, &m);
  for(i = 0; i < n; i++){
    scanf("%s", s);
    for(j = 0; j < m - 4; j++){
      s1[0] = s[j];
      s1[1] = s[j+1];
      s1[2] = s[j+2];
      s1[3] = s[j+3];
      s1[4] = '\0';
      if(strcmp(s1, "LOVE") == 0) flag = 1;
    }
  }
  if(flag == 1) printf("YES\n");
  else printf("NO\n");
  return 0;
}