from math import isqrt

lim = 10**7 + 10
prime_flag = [1]*lim
prime_flag[0] = 0
prime_flag[1] = 0

for p in range(2,lim):
    if prime_flag[p]:
        for q in range(2*p,lim,p):
            prime_flag[q] = 0

ans = [0]*lim
ans[0] = -1
t = int(input())
for i in range(t):
    n = int(input())
    r = isqrt(n+1)-1
    s = r
    while True:
        if ans[s] != 0:
            nans = ans[s]
            break
        if prime_flag[s] & prime_flag[s+2]:
            nans = s*(s+2)
            break
        s -= 1
    
    for i in range(s,r+1):
        ans[i] = nans
    print(nans)