function gridChallenge(grid) {
    const orderedArr = grid.map(row => row.split('').sort().join(''));
    for (let i = 0;i< grid.length;i++) {
        for (let j = 0;j< grid.length - 1;j++) {
            if (orderedArr[j][i] > orderedArr[j+1][i]) {
                return "NO";
            }
        }
    }
    return 'YES';
}