#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
const int maxn = 2e5 + 5;

int n;
ll c[maxn], pre[maxn], pre2[maxn], pre3[maxn], suf[maxn];

#define ls k << 1
#define rs k << 1 | 1

struct segtree
{
	struct segnode
	{
		int l, r;
		ll mx, lz;
	}t[maxn << 2];
	
	inline void pushup(int k) { t[k].mx = max(t[ls].mx, t[rs].mx); }
	inline void upd(int k, ll d) { t[k].mx += d; t[k].lz += d; }
	inline void pushdown(int k)
	{
		if (t[k].lz)
		{
			upd(ls, t[k].lz);
			upd(rs, t[k].lz);
			t[k].lz = 0;
		}
	}
	
	void build(int k, int l, int r)
	{
		t[k].l = l, t[k].r = r;
		if (l == r)
		{
			t[k].mx = pre[l] - pre2[min(n, 2 * l - 1)];
			return;
		}
		int mid = (l + r) >> 1;
		build(ls, l, mid);
		build(rs, mid + 1, r);
		pushup(k);
	}
	
	void update(int k, int l, int r, ll d)
	{
		if (l <= t[k].l && t[k].r <= r)
		{
			upd(k, d);
			return;
		}
		pushdown(k);
		int mid = (t[k].l + t[k].r) >> 1;
		if (l <= mid) update(ls, l, r, d);
		if (r > mid) update(rs, l, r, d);
		pushup(k);
	}
	
	ll query(int k, int l, int r)
	{
		if (l <= t[k].l && t[k].r <= r) return t[k].mx;
		pushdown(k);
		int mid = (t[k].l + t[k].r) >> 1; ll ans = 0;
		if (l <= mid) ans = max(ans, query(ls, l, r));
		if (r > mid) ans = max(ans, query(rs, l, r));
		return ans;
	}
}T;

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0); 
	
	int q;
	cin >> n >> q;
	for (int i = 1; i <= n; i++)
	{
		cin >> c[i];
		pre[i] = pre[i - 1] + c[i] / 2;
		pre2[i] = pre2[i - 1] + (c[i] & 1);
	}
	T.build(1, 1, n);
	
	
	ll sum = pre[n];
	while (q--)
	{
		int x, d;
		cin >> x >> d;
		sum -= c[x] / 2;
		T.update(1, x, n, -c[x] / 2);
		T.update(1, (x + 1) / 2, n, (c[x] & 1));
		c[x] += d;
		sum += c[x] / 2;
		T.update(1, x, n, c[x] / 2);
		T.update(1, (x + 1) / 2, n, -(c[x] & 1));
		cout << sum - T.t[1].mx / 3 << "\n";
	}
	return 0;
}