//  ↘ ⬇ ⬇ ⬇ ⬇ ⬇ ↙
//  ➡ @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"
#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--;
        a[x] += c;
        ac = a;
        int lft = 0;
        int res = 0;
        for (int j = 0; j < n; ++j) {
            int pp = min(lft, a[j] / 2);
            res += pp;
            lft -= pp;
            a[j] -= pp * 2;
            pp = a[j] / 3;
            res += pp;
            a[j] -= pp * 3;
            if (a[j] == 2) {
                for (int k = j+1; k <= min(n-1, j * 2); ++k) {
                    if (a[k]) {
                        a[k]--;
                        a[j] = 0;
                        res++;
                        break;
                    }
                }
            }
            lft += a[j];
        }
        cout << res << '\n';
        a = ac;
    }
}
signed main() {
    ios::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);
    int t = 1;
    while (t--) {
        solve();
    }
}
/*

 */