from itertools import permutations
def d(s,e):
    d=0
    while s!=e:
        x=1 if s[0]<e[0] else -1 if s[0]>e[0] else 0
        y=1 if s[1]<e[1] else -1 if s[1]>e[1] else 0
        s=(s[0]+x,s[1]+y)
        d+=(1,1.5)[x and y]
    return d
l,m=4,0
for o in permutations([(1,1),(2,2),(3,3)]):
    a,c=l-d((0,0),o[0]),1
    for j in range(len(o)-1):
        a-=d(o[j],o[j+1])
        c+=(0,1)[a>0]
    m=max(c,m)
print m