#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

constexpr int N = 2e5 + 10;

int n, q, c[N];

#define lson pos << 1
#define rson pos << 1 | 1

ll w[N << 2], lazy[N << 2];

inline void pushdown(int pos) {
    if (!lazy[pos]) return;
    w[lson] += lazy[pos], w[rson] += lazy[pos];
    lazy[lson] += lazy[pos], lazy[rson] += lazy[pos];
    lazy[pos] = 0;
}

void upd(int pos, int l, int r, int x, int y, int c) {
    if (x <= l && r <= y) {w[pos] += c, lazy[pos] += c; return;}
    pushdown(pos); int mid = (l + r) >> 1;
    if (x <= mid) upd(lson, l, mid, x, y, c);
    if (y > mid) upd(rson, mid + 1, r, x, y, c);
    w[pos] = min(w[lson], w[rson]);
}

int main() {
    ios_base::sync_with_stdio(0); cin.tie(nullptr), cout.tie(nullptr);
    cin >> n >> q; ll iso = 0;
    for (int i = 1; i <= n; i++) {
        cin >> c[i]; iso += c[i] >> 1;
        upd(1, 1, n, (i >> 1) + 1, n, c[i] & 1), upd(1, 1, n, i, n, -(c[i] >> 1));
    }
    while (q--) {
        int l, d; cin >> l >> d; iso -= c[l] >> 1;
        upd(1, 1, n, (l >> 1) + 1, n, -(c[l] & 1)), upd(1, 1, n, l, n, c[l] >> 1);
        c[l] += d; iso += c[l] >> 1;
        upd(1, 1, n, (l >> 1 + 1), n, c[l] & 1), upd(1, 1, n, l, n, -(c[l] >> 1));
        cout << (w[1] >= 0 ? iso : iso - (-w[1] + 2) / 3) << '\n';
    }
    return 0;
}