mapping = {
    0: 'o',
    1: 'a',
    2: 'b',
    3: 'k',
    4: 'i',
    5: 'j',
    6: 'l',
    7: 'd',
    8: 'e',
    9: 'f'
}

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