import std;

void main() {
    int n, m; scan(n, m);

    bool found = false;
    foreach (_; 0..n) {
        string s = readln.chomp;
        if (s.canFind("LOVE")) {
            found = true;
            break;
        }
    }
    writeln(found ? "YES" : "NO");
}

void scan(T...)(ref T a) {
    string[] ss = readln.split;
    foreach (i, t; T) a[i] = ss[i].to!t;
}
T read(T)() { return readln.chomp.to!T; }
T[] reads(T)() { return readln.split.to!(T[]); }
alias readint = read!int;
alias readints = reads!int;