#!/usr/bin/python3

# https://www.hackerrank.com/challenges/halloween-party

import sys

def count_gems(str, gems):
    tmp = [ False ] * 26
    for c in str:
        tmp[ord(c) - 97] = True
    for i in range(26):
        if not tmp[i]:
            gems[i] = False

def main():
    N = int(sys.stdin.readline())
    gems = [ True ] * 26
    for _ in range(N):
        str = sys.stdin.readline().strip()
        count_gems(str, gems)
    print(sum(gems))

if __name__ == '__main__':
    main()