//  ↘ ⬇ ⬇ ⬇ ⬇ ⬇ ↙
//  ➡ @roadfromroi ⬅
//  ↗ ⬆ ⬆ ⬆ ⬆ ⬆ ↖
#include <iostream>
#include "vector"
#include "algorithm"
#include "numeric"
#include "climits"
#include "iomanip"
#include "bitset"
#include "cmath"
#include "map"
#include "deque"
#include "array"
#include "set"
#include "queue"
#define all(x) x.begin(), x.end()
using namespace std;
#define int long long
struct segtree {
    int sz;
    vector<int> tree, addk;
    segtree(int n) {
        sz = 1;
        while (sz < n)
            sz *= 2;
        tree.assign(sz * 2, {});
        addk.assign(sz * 2, {});
    }
    int getv(int v) {
        return tree[v] + addk[v];
    }
    void push(int v) {
        addk[v * 2] += addk[v];
        addk[v * 2 + 1] += addk[v];
        addk[v] = 0;
    }
    void pull(int v) {
        tree[v] = min(getv(v * 2), getv(v * 2 + 1));
    }
    void add2(int l, int r, int v, int ll, int rr, int x) {
        if (ll >= r or rr <= l) {
            return;
        }
        //cerr << l << ' ' << r << v << '\n';
        if (ll <= l and r <= rr) {
            //cerr << v << ' ' << x << '\n';
            addk[v] += x;
            return;
        }
        push(v);
        int m = l + r >> 1;
        add2(l, m, v * 2, ll, rr, x);
        add2(m, r, v * 2 + 1, ll, rr, x);
        pull(v);

    }
    void add(int l, int r, int x) {
        return add2(0, sz, 1, l, r+1, x);
    }
   
    int get() {
        return min(0ll, getv(0));
    }
};
void solve() {
    int n, q;
    cin >> n >> q;
    vector<int> a(n), ac;
    int sm = 0;
    int twdd = 0, ondd = 0;
    segtree sg(n);
    for (int i = 0; i < n; ++i) {
        cin >> a[i];
        sm += a[i];
        twdd += a[i] / 2;
        sg.add(0, min(n-1, i * 2), a[i] / 2);
        if (a[i] % 2) {
            ondd++;
            sg.add(0, i, -1);
        }
    }
    for (int i = 0; i < q; ++i) {
        int x, c;
        cin >> x >> c;
        x--;
        twdd -= a[x] / 2;
        sg.add(0, min(n-1, x * 2), -a[x] / 2);
        if (a[x] % 2) {
            ondd--;
            sg.add(0, x, 1);
        }
        a[x] += c;
        twdd += a[x] / 2;
        sm += c;
        sg.add(0, min(n-1, x * 2), a[x] / 2);
        if (a[x] % 2) {
            ondd++;
            sg.add(0, x, -1);
        }
        int rs = sg.get();
        int lft = -rs;
        int tw2 = twdd - (ondd - lft);
        //cout << sm << ' ' << tw2 << ' ' << lft << ' ' << tw2 << '\n';
        cout << (sm - lft - (tw2 * 2 % 3)) / 3 << '\n';
    }
}

signed main() {
    ios::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);
    int t = 1;
    while (t--) {
        solve();
    }
}
/*
4 3
3 1 4 1
3 -3
1 6
2 1
 */