import sys
input = lambda :sys.stdin.readline()[:-1]
ni = lambda :int(input())
na = lambda :list(map(int,input().split()))
yes = lambda :print("yes");Yes = lambda :print("Yes");YES = lambda : print("YES")
no = lambda :print("no");No = lambda :print("No");NO = lambda : print("NO")
#######################################################################

def ask(x):
    print(x, flush=True)
    r = ni()
    if r == 1:
        exit()
    if r == -1:
        exit()
    return r

m = 30
for i in range(m-1, -1, -1):
    ask(1 << i)