v=[0]*(10**7+10**6)
for x in range(2,10**7+10**6):
  if v[x]==1:
    continue
  for y in range(2,10**7):
    if x*y>=10**7+10**6:
      break
    v[x*y]=1
p=[]
for x in range(2,10**7+10**6-1):
  if v[x]==0 and v[x+2]==0:
    p.append(x)
Q=int(input())
from math import isqrt
from bisect import bisect_right
for _ in range(Q):
  N=int(input())
  K=isqrt(N)
  pos=bisect_right(p,K)
  result=-1
  for e in range(pos-5,pos+5):
    if e<0:
      continue
    x=p[e]
    if x*(x+2)<=N:
      result=max(result,x*(x+2))
  print(result)