N = int(input())

dat = [0] * (N + 1)
C = N + 1
prime = []
for i in range(2,C):
    if dat[i] == 0:
        u = i
        while u < N:
            u *= i
        prime.append(u)
        for j in range(2 * i,C,i):
            dat[j] = 1
ans = 1
for i in range(0,len(p),3):
    tmp = p[i]
    if i + 1 < len(p):
        tmp *= p[i+1]
    if i + 2 < len(p):
        tmp *= p[i+2]
    print("?",tmp)
    ans *= int(input())
print(ans)