# Predefined mapping based on the given examples
digit_map = [''] * 10
digit_map[3] = 'k'
digit_map[4] = 'i'
digit_map[7] = 'd'
digit_map[8] = 'e'

while True:
    line = input().strip()
    if not line:
        continue
    num = int(line)
    if num == 0:
        break
    print(digit_map[num])