public String check(String word) {
		char[] charArray = word.toCharArray();

		int point = 0;
		while (point < charArray.length) {
			if (charArray[point] == 'p' && charArray[point + 1] == 'i') {
				point += 2;
			}
			else if (charArray[point] == 'k' && charArray[point + 1] == 'a') {
				point+=2;
			}
			else if (charArray[point] == 'c' && charArray[point + 1] == 'h' &&  charArray[point + 2] == 'u') {
				point+=3;
			}
			else {
				return "NO";
			}
		}
		return "YES";
	}