I,R=input,range
N=int(I())
c=[0]*10
b=[0]*40
for s in I():c[int(s)]+=1
for n in R(1000):
	T,m=[0]*10,n
	while m:
		T[m%10]+=1
		m//=10
	b[n%40]|=(sum(T)==min(N,3))*all(T[i]<=c[i]for i in R(10))
print(sum(b))