# oj t -c "python3 main.py"
import sys,math
from collections import defaultdict,deque
from itertools import combinations,permutations,accumulate,product
from bisect import bisect,bisect_left,bisect_right
from heapq import heappop,heappush,heapify
#from sortedcontainers import SortedList,SortedSet
def input(): return sys.stdin.readline().rstrip()
def ii(): return int(input())
def ms(): return map(int, input().split())
def li(): return list(map(int,input().split()))
inf = pow(10,18)
#////////////////////////////////////
N = ii()
S = input()
cnt = defaultdict(int)
for s in S:
  cnt[s] += 1
alp = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
for a in alp:
  print(cnt[a],end='')