n = int(eval(input()))

chars = "Xabcdefghijklmnopqrstuvwxyz"  



n_rem = n  

res = ""



while True:

    x = n_rem % 26

   

    if x == 0:

        x = 26

    res += chars[x]



    

    n_rem -= x



    

    if n_rem == 0:

        break



    n_rem //= 26





print((res[::-1]))
N = int(eval(input()))



chars = "Xabcdefghijklmnopqrstuvwxyz"

result = ""

n_1 = N



while True:

    x = n_1 % 26



    if x == 0:

        x = 26



    result += chars[x]

    n_1 -= x

    if n_1 == 0:

        break



    n_1 //= 26



print((result[::-1]))



n = int(eval(input()))
chars = "Xabcdefghijklmnopqrstuvwxyz"
n_rem = n
res = ""
while True:
    x = n_rem % 26
    if x == 0:
        x = 26
    res += chars[x]
    n_rem -= x
    if n_rem == 0:
        break
    n_rem //= 26
print((res[::-1]))

N = int(eval(input()))
chars = "Xabcdefghijklmnopqrstuvwxyz"
result = ""
n_1 = N
while True:
    x = n_1 % 26
    if x == 0:
        x = 26
    result += chars[x]
    n_1 -= x
    if n_1 == 0:
        break
    n_1 //= 26
print((result[::-1]))

-n = int(eval(input())) +N = int(eval(input())) -n_rem = n -res = "" +result = "" +n_1 = N -    x = n_rem % 26 +    x = n_1 % 26 -    res += chars[x] -    n_rem -= x -    if n_rem == 0: +    result += chars[x] +    n_1 -= x +    if n_1 == 0: -    n_rem //= 26 -print((res[::-1])) +    n_1 //= 26 +print((result[::-1]))