You are given a string *q*. A sequence of *k* strings *s*<sub class="lower-index">1</sub>, *s*<sub class="lower-index">2</sub>, ..., *s*<sub class="lower-index">*k*</sub> is called beautiful, if the concatenation of these strings is string *q* (formally, *s*<sub class="lower-index">1</sub> + *s*<sub class="lower-index">2</sub> + ... + *s*<sub class="lower-index">*k*</sub> = *q*) and the first characters of these strings are distinct.

Find any beautiful sequence of strings or determine that the beautiful sequence doesn't exist.
The first line contains a positive integer *k* (1 ≤ *k* ≤ 26) — the number of strings that should be in a beautiful sequence. 

The second line contains string *q*, consisting of lowercase Latin letters. The length of the string is within range from 1 to 100, inclusive.
import sys


def main():
    k = int(input())
    w = input()
    mark = {}
    distict = 0
    for i in range(len(w)):
        if w[i] not in mark:
            mark[w[i]] = True
            distict += 1
    if distict < k:
        print('NO')
    else:
        curr = None
        for i in range(len(w)):
            if k == 0:
                sys.stdout.write(w[i])
            elif curr != w[i]:
                # print(w[i], k)
                curr = w[i]
                k -= 1
                if i != 0:
                    print()
                sys.stdout.write(w[i])
            else:
                sys.stdout.write(w[i])


main()
