n, m = map(int, input().split())
tree = (2**n) * [0]
vals = (2**n) * [1]
out = []

for i in range(2**(n-1) - 1, 0, -1):
    tree[i] = max(tree[2*i], tree[2*i+1]) + vals[i]

def update(idx, new_val):
    vals[idx] = new_val
    j = idx
    while j > 0:
        if j <= 2**(n-1) - 1:
            tree[j] = max(tree[2 * j] + vals[2 * j], tree[2 * j + 1] + vals[2*j + 1])
        else:
            tree[j] = 0
        j = j // 2
    out.append(tree[1])

for _ in range(m):
    index, val = map(int, input().split())
    update(index, val)

for i in out:
    print(i)