import re

def check_number_divisible_by_5(input_string):
    pattern = r'^(hi){2,}\!*$'

    if re.match(pattern, input_string):
        print('yes')
    else:
        print('no')

if __name__ == "__main__":
    try:
        while True:
            line = input()
            check_number_divisible_by_5(line)

    except EOFError:
        pass