#include <iostream>
#include <vector>
#include <string>
#include <algorithm>

int main(int argc, char * argv[])
{
    int n, m;
    std::cin >> n >> m;
    std::vector<std::string> lines;
    lines.resize(m);
    for (int i = 0; i < n; i++) {
        std::cin >> lines[i];
    }
    for (auto&& s : lines) {
        if (s.find("LOVE") != std::string::npos) {
            std::cout << "YES" << std::endl;
            return 0;
        }
    }
    std::cout << "NO" << std::endl;
    return 0;
}