# Task
 The sequence of `Chando` is an infinite sequence of all Chando's numbers in ascending order.
 A number is called `Chando's` if it is an integer that can be represented as a sum of different positive integer powers of 5.
 The first Chando's numbers is 5 (5^1). And the following nth Chando's numbers are:
 ```
 25  (5^2)
 30  (5^1 + 5^2)
 125 (5^3)
 130 (5^1 + 5^3)
 150 (5^2 + 5^3)
 ...
 ...
 ```
 Your task is to find the Chando's nth number for a given `n`.
# Input/Output
 - `[input]` integer `n`
  `1 <= n <= 7000`
 - `[output]` an integer
  nth Chando's number
from itertools import combinations as c
def nth_chandos_number(n):
    comb, generate, i = [1], [], 1
    while len(generate) <= n:
        generate.extend(sorted([j for k in range(1,len(comb)+1) for j in c(comb,k) if j[0]==i]))
        i += 1  ; comb.insert(0, i)
    return sum(5 ** i for i in generate[n-1])
from itertools import combinations as c
def nth_chandos_number(n):
    comb, generate, i = [1], [], 1
    while len(generate) <= n:
        generate.extend(sorted([j for k in range(1,len(comb)+1) for j in c(comb,k) if j[0]==i]))
        i += 1  ; comb.insert(0, i)
    return sum(5 ** i for i in generate[n-1])