Problem:
Score : 300 points

Problem Statement

1000000000000001 dogs suddenly appeared under the roof of Roger's house, all of which he decided to keep. The dogs had been numbered 1 through 1000000000000001, but he gave them new names, as follows:

the dogs numbered 1,2,\cdots,26 were respectively given the names a, b, ..., z;

the dogs numbered 27,28,29,\cdots,701,702 were respectively given the names aa, ab, ac, ..., zy, zz;

the dogs numbered 703,704,705,\cdots,18277,18278 were respectively given the names aaa, aab, aac, ..., zzy, zzz;

the dogs numbered 18279,18280,18281,\cdots,475253,475254 were respectively given the names aaaa, aaab, aaac, ..., zzzy, zzzz;

the dogs numbered 475255,475256,\cdots were respectively given the names aaaaa, aaaab, ...;

and so on.

To sum it up, the dogs numbered 1, 2, \cdots were respectively given the following names:

a, b, ..., z, aa, ab, ..., az, ba, bb, ..., bz, ..., za, zb, ..., zz, aaa, aab, ..., aaz, aba, abb, ..., abz, ..., zzz, aaaa, ...

Now, Roger asks you:

"What is the name for the dog numbered N?"

Constraints

N is an integer.

1 \leq N \leq 1000000000000001

Input

Input is given from Standard Input in the following format:

N

Output

Print the answer to Roger's question as a string consisting of lowercase English letters.

Sample Input 1

2

Sample Output 1

b

Sample Input 2

27

Sample Output 2

aa

Sample Input 3

123456789

Sample Output 3

jjddja

Solution in Ruby (2.7.1) (judge verdict: Runtime Error)

n = gets.chomp.to_i
i = 26
j = 26
ii = [0]
ii << i
count = 1
arr = []
while true
if n < j
    arr << j
    break
end
count += 1
i = i * 26    
j = i  + j
ii << j
end
p ii
puts count
puts arr
puts "hhhhhhhhhhhhhhhhhhhhhhhhh"
a_z = [*"a".."z"]
matome = []
jj = 0
#while i > 0
2.times do
    if jj <= 0
        kazubanngou = n - ii[count-1]
    end
    if jj > 0
        kazubanngou = n - sa
    end
puts "AAAAAAAAAAAAA"
puts kazubanngou
puts "BBBBBBBBBBBB"
aaa_azz = ii[count-1]-ii[count-2] + 1
puts aaa_azz
ichibannme_amari = kazubanngou % aaa_azz
puts "CCCCCCCCCC"
puts ichibannme_amari
puts "DDDDDDDDDDD"
a_zkimeru = (kazubanngou - ichibannme_amari) / aaa_azz
# puts a_zkimeru
# puts "ZZZZZZZZZZ"
matome << a_z[a_zkimeru]
count -= 1
sa = a_zkimeru * aaa_azz
jj += 1
end
p matome