# 1470 Mex Sum

from scipy.special import comb
from sys import stdin

n=int(stdin.readline())
a=tuple(map(int,stdin.readline().split()))

classifiedA=[0]*(3+1)
for e in a:
    if e==1:
        classifiedA[1]+=1
    elif e==2:
        classifiedA[2]+=1
    else:
        classifiedA[3]+=1
        
sumA=0
sumA+=3*classifiedA[1]*classifiedA[2]
sumA+=2*(comb(classifiedA[1],2,exact=True)+(classifiedA[1]*classifiedA[3]))
sumA+=1*(comb(classifiedA[2],2,exact=True)+comb(classifiedA[3],2,exact=True)+(classifiedA[2]*classifiedA[3]))
print(sumA)