const lines = require('fs')
  .readFileSync('/dev/stdin', 'utf-8')
  .trim().split('\n').values();

const [n, m] = lines.next().value
  .split(' ').map(x => Number(x));

for (let i = 0; i < n; i++) {
  if (lines.next().value.indexOf('LOVE') >= 0) {
    console.log('YES');
    return;
  }
}

console.log('NO');