#include <iostream>
#define FOR(i,x,y) for(int i=x;i<y;i++)
using namespace std;
int main(){
    int n,m;
    string s;
    cin>>n>>m;
    
    FOR(i,0,n){
        cin>>s;
        FOR(j,0,m-3){
            if(s.substr(j,4)=="LOVE"){
                cout<<"YES"<<endl;
                exit(0);
            }
        }
    }
    cout<<"NO"<<endl;
}