#==================================================
def send(i,k):
    print(i,k, flush=True)

def recieve():
    i,k=map(int,input().split())
    return i,k

def phase():
    return int(input())

def choice(turn):
    print(turn, flush=True)

def bit(x,k):
    return (x>>k)&1

#==================================================
def solve():
    N=int(input())
    A=[0]+list(map(int,input().split()))

    grundy=0; B=17
    S=[set([i for i in range(1,N+1) if bit(A[i],t)]) for t in range(B)]

    for a in A[1:]:
        grundy^=a

    turn=1 if grundy else 0
    choice(turn)

    while True:
        if turn:
            msb=grundy.bit_length()-1
            i=S[msb].pop()
            a=A[i]
            b=grundy^A[i]
            k=A[i]-b

            send(i,k)
        else:
            i,k=recieve()

        for t in range(B):
            S[t].discard(i)

        grundy^=A[i]^(A[i]-k)
        A[i]-=k

        for t in range(B):
            if bit(A[i],t):
                S[t].add(i)

        if phase()==-1:
            return
        turn^=1

#==================================================
solve()