//  ↘ ⬇ ⬇ ⬇ ⬇ ⬇ ↙
//  ➡ @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
void solve() {
    int n, q;
    cin >> n >> q;
    vector<int> a(n), ac;
    for (int i = 0; i < n; ++i) {
        cin >> a[i];
    }
    for (int i = 0; i < q; ++i) {
        int x, c;
        cin >> x >> c;
        x--;
        queue<pair<int, int>> que;
        a[x] += c;
        ac = a;
        int lft = 0;
        int res = 0;
        for (int j = 0; j < n; ++j) {
            if (j % 2 == 1 and !que.empty() and que.front().first == j / 2) {
                int pt = que.front().second * 2 / 3;
                res += pt;
                lft += que.front().second * 2 % 3;
                que.pop();
                while (!que.empty() and lft != 0) {
                    int vl = min(que.front().second, lft);
                    que.front().second -= vl;
                    lft -= vl;
                    res += vl;
                    if (que.front().second == 0)
                        que.pop();
                }
            }
            int qq = min(lft, a[j] / 2);
            lft -= qq;
            a[j] -= qq * 2;
            res += qq;
            if (a[j] >= 2) {
                que.push({j, a[j] / 2});
                a[j] %= 2;
            }
            if (a[j]) {
                if (!que.empty()) {
                    que.front().second--;
                    if (que.front().second == 0)
                        que.pop();
                    res++;
                } else {
                    lft++;
                }
            }
        }
        cout << res << '\n';
        a = ac;
    }
}
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
 */