#!/usr/bin/env python3.7
# Converts base-A to base-B number systems,
#   where A and B are between 2 and 36.
# This code will only convert whole numbers.


# get inputs
print("")
print("2 <= base <= 36")
A = int(input("  base initial = "))
if A<2 or A>36:
  print("input error")
  quit()
B = int(input("  base final = "))
if B<2 or B>36:
  print("input error")
  quit()
print("using 0,1,...,9,A,B,...,Z")
try:    # Python 2
  str1 = str.upper(raw_input("  number in base "+str(A)+" = "))
except: # Python 3
  str1 = str.upper(input("  number in base "+str(A)+" = "))
str2 = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"
print("")


# convert str1 to number
number = 0
for i in range(len(str1)):
  value = str2.index(str1[i])
  if value >= A:
    print("input error")
    quit()
  number += A**(len(str1)-i-1) * value
print("in base 10: "+str(number))


# convert number to string in final base
x = 0   # x+1 will be the length of str3
while number/B**x>=B:
  x+=1
str3 = ''
for i in range(x,-1,-1):   # x, x-1, ..., 1, 0
  temp = int(number/B**i)
  number = number - temp * B**i
  str3 += str2[temp]
print("in base "+str(B)+": "+str3)
print("")