# Read numbers until 0 is encountered and map them to corresponding letters
mapping = {
    3: 'k',
    4: 'i',
    7: 'd',
    8: 'e'
}

while True:
    line = input().strip()
    if not line:
        continue
    num = int(line)
    if num == 0:
        break
    print(mapping.get(num, ''))