def solution(files):
fn_order_list = [] * len(files)
head_list = {}
num_list = {}
tail_list = {}
head = ""
num = ""
tail = ""
for f in files :
n_start_index = 0
for s in f :
if !s.isdigit() :
head += s
n_start_index += 1
t_start_index
for s in f[n_start_index] :
if s.isdigit() :
num += s
t_start_index +=1
tail += f[n_start_index+t_start_index]
head_list[f] = head
num_list[f] = num
tail_list[f] = tail
head_list.sort
answer = []
return answer