n = int(input())
aa = list(map(int, input().split()))

ii = [set() for _ in range(18)]
def push(i, a):
    aa[i] = a
    for j in range(18):
        if a & 1: ii[j].add(i)
        a >>= 1

def get(x):
    j = x.bit_length()-1
    i = ii[j].pop()
    rem(i)
    return i

def rem(i):
    for j in range(18):
        ii[j].discard(i)

x = 0
for i, a in enumerate(aa):
    x ^= a
    push(i, a)

t = 1 if x else 0
print(t, flush=True)

ret = 0
while ret == 0:
    if t:
        i = get(x)
        a = aa[i]
        b = x ^ a
        k = a-b
        print(i+1, k, flush=True)
    else:
        i, k = map(int, input().split())
        i -= 1
        a = aa[i]
        rem(i)
        b = a-k
    x ^= a ^ b
    push(i, b)
    ret = int(input())
    t ^= 1