#include <iostream>
#include <algorithm>
#include <cmath>
#include <fstream>
#include <queue>
#define ll long long

using namespace std;

ifstream beir("fa.in");

vector <ll> mag, x;
deque <ll> v;

void magassag(ll csp, ll n)
{
    v.pop_front();
    if(csp >= n)
    {
        mag[csp] = x[csp];
        return;
    }
    if(v.front() == 0)
        magassag(2*csp, n);
    else
        magassag(2*csp+1, n);
    mag[csp] = max(mag[csp*2], mag[csp*2+1]) + x[csp];
}

int main()
{
    ll n, csp, k, j, g;
    beir >> n >> k;
    csp = pow(2, n) - 1;
    x.assign(csp+1, 1);
    mag.resize(csp+1);
    x[1] = 0;
    for(ll i=1; i<=k; ++i)
    {
        beir >> j >> g;
        x[j] = g;
        while(j)
        {
            v.push_front(j % 2);
            j /= 2;
        }
        magassag(1, pow(2, n-1));
        cout << mag[1] << endl;
        v.clear();
    }

    return 0;
}