S = input
R = range
P = print
def I(): return int(S())
def M(): return map(int, S().split())
def L(): return list(M())
def O(): return list(map(int, open(0).read().split()))
def yn(b): print("Yes" if b else "No")
biga = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
smaa = "abcdefghijklmnopqrstuvwxyz"

n = I()
s = S()
c = [0] * 26
for i in s:
	c[ord(i) - ord('A')] += 1
P(''.join(map(str, c)))