Buggy python submission (verdict: Runtime Error):
import bisect
a=[]
def f(n,p):
    m=-1<<20
    x=bisect.bisect_left(a,n)
    if a[x]==n:m=1
    if a[p]**2>n:return m
    if n%a[p]==0:m=f(n//a[p],p)+1
    return max(m,f(n,p+1))

for i in range(1,19):
    for j in range(1<<i):
        b=''
        for k in range(i):
            if (j//(1<<k))%2:b+='2'
            else:b+='8'
        a+=[int(b)]
a.sort()
n=int(input())
b=f(n,0)
if n==1 or b<0:b=-1
print(b)

Fixed submission:
import bisect
import sys
sys.setrecursionlimit(10000)
a=[]
def f(a,bin,n):
    if bin>n:return
    if bin:a+=[bin]
    f(a,bin*10+2,n)
    f(a,bin*10+8,n)

def g(n,p):
    m=-1<<20
    x=bisect.bisect_left(a,n)
    if x!=len(a) and a[x]==n:m=1
    if a[p]**2>n:return m
    if n%a[p]==0:m=g(n//a[p],p)+1
    return max(m,g(n,p+1))

n=int(input())
if n&1:print(-1);exit()
f(a,0,n)
a=sorted(a)
b=g(n,0)
if b<0:b=-1
print(b)

Buggy python submission (verdict: Runtime Error):
import bisect
a=[]
def f(n,p):
    m=-1<<20
    x=bisect.bisect_left(a,n)
    if a[x]==n and x!=len(a):m=1
    if a[p]**2>n:return m
    if n%a[p]==0:m=f(n//a[p],p)+1
    return max(m,f(n,p+1))

for i in range(1,19):
    for j in range(1<<i):
        b=''
        for k in range(i):
            if (j//(1<<k))%2:b+='2'
            else:b+='8'
        a+=[int(b)]
a.sort()
n=int(input())
b=f(n,0)
if n==1 or b<0:b=-1
print(b)

Fixed submission:
import bisect
import sys
sys.setrecursionlimit(10000)
a=[]
def f(a,bin,n):
    if bin>n:return
    if bin:a+=[bin]
    f(a,bin*10+2,n)
    f(a,bin*10+8,n)

def g(n,p):
    m=-1<<20
    x=bisect.bisect_left(a,n)
    if x!=len(a) and a[x]==n:m=1
    if a[p]**2>n:return m
    if n%a[p]==0:m=g(n//a[p],p)+1
    return max(m,g(n,p+1))

n=int(input())
if n&1:print(-1);exit()
f(a,0,n)
a=sorted(a)
b=g(n,0)
if b<0:b=-1
print(b)

Buggy python submission (verdict: Runtime Error):
import bisect
a=[]
def f(a,bin,n):
    if bin>n:return
    if bin:a+=[bin]
    f(a,bin*10+2,n)
    f(a,bin*10+8,n)

def g(n,p):
    m=-1<<20
    x=bisect.bisect_left(a,n)
    if x!=len(a) and a[x]==n:m=1
    if a[p]**2>n:return m
    if n%a[p]==0:m=g(n//a[p],p)+1
    return max(m,g(n,p+1))

n=int(input())
if n&1:print(-1);exit()
f(a,0,n)
a.sort()
b=g(n,0)
if b<0:b=-1
print(b)

Fixed submission:
import bisect
import sys
sys.setrecursionlimit(10000)
a=[]
def f(a,bin,n):
    if bin>n:return
    if bin:a+=[bin]
    f(a,bin*10+2,n)
    f(a,bin*10+8,n)

def g(n,p):
    m=-1<<20
    x=bisect.bisect_left(a,n)
    if x!=len(a) and a[x]==n:m=1
    if a[p]**2>n:return m
    if n%a[p]==0:m=g(n//a[p],p)+1
    return max(m,g(n,p+1))

n=int(input())
if n&1:print(-1);exit()
f(a,0,n)
a=sorted(a)
b=g(n,0)
if b<0:b=-1
print(b)

Buggy python submission (verdict: Runtime Error):
import bisect
a=[]
def f(a,bin,n):
    if bin>n:return
    if bin:a+=[bin]
    f(a,bin*10+2,n)
    f(a,bin*10+8,n)

def g(n,p):
    m=-1<<20
    x=bisect.bisect_left(a,n)
    if x!=len(a) and a[x]==n:m=1
    if a[p]**2>n:return m
    if n%a[p]==0:m=g(n//a[p],p)+1
    return max(m,g(n,p+1))

n=int(input())
if n&1:print(-1);exit()
f(a,0,n)
a=sorted(a)+[10**20]
b=g(n,0)
if b<0:b=-1
print(b)

Fixed submission:
import bisect
import sys
sys.setrecursionlimit(10000)
a=[]
def f(a,bin,n):
    if bin>n:return
    if bin:a+=[bin]
    f(a,bin*10+2,n)
    f(a,bin*10+8,n)

def g(n,p):
    m=-1<<20
    x=bisect.bisect_left(a,n)
    if x!=len(a) and a[x]==n:m=1
    if a[p]**2>n:return m
    if n%a[p]==0:m=g(n//a[p],p)+1
    return max(m,g(n,p+1))

n=int(input())
if n&1:print(-1);exit()
f(a,0,n)
a=sorted(a)
b=g(n,0)
if b<0:b=-1
print(b)

Buggy python submission (verdict: Runtime Error):
import bisect
a=[]
def f(a,bin,n):
    if bin>n:return
    if bin:a+=[bin]
    f(a,bin*10+2,n)
    f(a,bin*10+8,n)

def g(n,p):
    m=-1<<20
    x=bisect.bisect_left(a,n)
    if p>len(a):return m
    if x!=len(a) and a[x]==n:m=1
    if a[p]**2>n:return m
    if n%a[p]==0:m=g(n//a[p],p)+1
    return max(m,g(n,p+1))

n=int(input())
if n&1:print(-1);exit()
f(a,0,n)
a=sorted(a)+[10**20]
b=g(n,0)
if b<0:b=-1
print(b)

Fixed submission:
import bisect
import sys
sys.setrecursionlimit(10000)
a=[]
def f(a,bin,n):
    if bin>n:return
    if bin:a+=[bin]
    f(a,bin*10+2,n)
    f(a,bin*10+8,n)

def g(n,p):
    m=-1<<20
    x=bisect.bisect_left(a,n)
    if x!=len(a) and a[x]==n:m=1
    if a[p]**2>n:return m
    if n%a[p]==0:m=g(n//a[p],p)+1
    return max(m,g(n,p+1))

n=int(input())
if n&1:print(-1);exit()
f(a,0,n)
a=sorted(a)
b=g(n,0)
if b<0:b=-1
print(b)