import sys
input = sys.stdin.readline

n = int(input())
a = list(map(int, input().split()))
x = 0

for ai in a:
    x ^= ai

t = 1 if x!=0 else 0
print(t)
turn = 0

while True:
    if turn^t:
        for i in range(n):
            if a[i]>x^a[i]:
                k = a[i]-(x^a[i])
                print(i+1, k)
                sys.stdout.flush()
                x ^= a[i]
                a[i] -= k
                x ^= a[i]
                break
    else:
        i, k = map(int, input().split())
        x ^= a[i-1]
        a[i-1] -= k
        x ^= a[i-1]
    
    ret = int(input())
    
    if ret==-1:
        exit()
    
    turn ^= 1