import sys, math
sys.setrecursionlimit(10**8)
sys.set_int_max_str_digits(0)
INF = 1e18
MOD = 120
from bisect import bisect_left, bisect_right
from collections import deque, defaultdict, Counter
from itertools import product, combinations, permutations, groupby, accumulate
from heapq import heapify, heappop, heappush
input = sys.stdin.readline
def I():   return input().rstrip()
def II():  return int(input().rstrip())
def IS():  return input().rstrip().split()
def MII(): return map(int, input().rstrip().split())
def LI():  return list(input().rstrip())
def TII(): return tuple(map(int, input().rstrip().split()))
def LII(): return list(map(int, input().rstrip().split()))
def LSI(): return list(map(str, input().rstrip().split()))
def GMI(): return list(map(lambda x: int(x) - 1, input().rstrip().split()))
def kiriage(a, b): return (a+b-1)//b

N = II()
S = LI()
c = Counter(S)

ans = [False] * 40
for i in range(1, 1000):
    if '0' in str(i).zfill(3):
        continue
    c2 = Counter(str(i))
    for k, v in c2.items():
        if c[k] >= v:
            continue
        else:
            break
    else:
        ans[i%40] = True

print(ans.count(True))