#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

const int N = 2005;

int n, q;
ll c[N];
ll a[N], b[N];

bool check(ll ps) {
	for (int i = n; i >= 1; --i) {
		b[i] = min(c[i] / 2, ps);
		ps -= b[i];
		a[i] = c[i] - 2 * b[i];
	}
	ll sum = 0;
	for (int i = 1; i <= n; ++i) {
		sum -= b[i];
		for (int j = (i - 1) * 2; j < i * 2; ++j) {
			sum += a[j];
		}
		if (sum < 0) {
			return false;
		}
	}
	return true;
}

void solve() {
	ll ps = 0;
	for (int i = 1; i <= n; ++i) {
		ps += c[i] / 2;
	}
	ll l = 0, r = ps + 1;
	while (r - l > 1) {
		ll mid = (l + r) / 2;
		if (check(mid)) {
			l = mid;
		} else {
			r = mid;
		}
	}
	cout << l << "\n";
}

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	cin >> n >> q;
	for (int i = 1; i <= n; ++i) {
		cin >> c[i];
	}
	while (q--) {
		int l;
		ll d;
		cin >> l >> d;
		c[l] += d;
		solve();
	}
	return 0;
}