#ifndef SorahISA
#define SorahISA
#include SorahISA __FILE__ SorahISA

void solve() {
    int N, Q; cin >> N >> Q;
    
    vector<int> C(N+1);
    for (int i = 1; i <= N; ++i) cin >> C[i];
    
    for (int q = 1; q <= Q; ++q) {
        int l, d; cin >> l >> d, C[l] += d;
        
        int ans = 0;
        auto L = C;
        for (int i = 1, j = 1, k = 1; i <= N; ++i) {
            if (L[i] < 2) continue;
            while (L[i] >= 2) {
                while (j <= min(2*i-1, N) and L[j] != 1) ++j;
                while (k <= min(2*i-1, N) and L[k] == (k == i ? 2 : 0)) ++k;
                
                if (k < i) {
                    int cnt = (k == i ? L[i] / 3 : min(L[i] / 2, L[k]));
                    L[i] -= 2 * cnt, L[k] -= cnt, ans += cnt;
                    // debug(i, i, k, cnt);
                }
                else if (k <= min(2*i-1, N) and L[k] == 1) {
                    L[i] -= 2, L[k] -= 1, ans += 1;
                    // debug(i, i, k, 1);
                }
                else if (j <= min(2*i-1, N)) {
                    L[i] -= 2, L[j] -= 1, ans += 1;
                    // debug(i, i, j, 1);
                }
                else if (k <= min(2*i-1, N)) {
                    int cnt = (k == i ? L[i] / 3 : min(L[i] / 2, L[k]));
                    L[i] -= 2 * cnt, L[k] -= cnt, ans += cnt;
                    // debug(i, i, k, cnt);
                }
                else {
                    break;
                }
            }
        }
        cout << ans << "\n";
    }
}

int32_t main() {
    fastIO();
    
    int t = 1; // cin >> t;
    for (int _ = 1; _ <= t; ++_) {
        solve();
    }
    
    return 0;
}

#else

#ifdef local
#define _GLIBCXX_DEBUG 1
#endif
#pragma GCC optimize("Ofast", "unroll-loops")
#include <bits/stdc++.h>
using namespace std;

using i64 = long long;
#define int i64
using f80 = long double;
#define double f80
using pii = pair<int, int>;
template <typename T> using Prior = std::priority_queue<T>;
template <typename T> using prior = std::priority_queue<T, vector<T>, greater<T>>;

#define eb emplace_back
#define ef emplace_front
#define ee emplace
#define pb pop_back
#define pf pop_front
#define ALL(x) begin(x), end(x)
#define RALL(x) rbegin(x), rend(x)
#define SZ(x) ((int)(x).size())

#ifdef local
#define fastIO() void()
#define debug(...) \
    fprintf(stderr, "\u001b[33m"), \
    fprintf(stderr, "At [%s], line %d: (%s) = ", __FUNCTION__, __LINE__, #__VA_ARGS__), \
    _do(__VA_ARGS__), \
    fprintf(stderr, "\u001b[0m")
template <typename T> void _do(T &&_t) { cerr << _t << "\n"; }
template <typename T, typename ...U> void _do(T &&_t, U &&..._u) { cerr << _t << ", ", _do(_u...); }
#else
#define fastIO() ios_base::sync_with_stdio(0), cin.tie(0)
#define debug(...) void()
#endif

template <typename T, typename U> bool chmin(T &lhs, U rhs) { return lhs > rhs ? lhs = rhs, 1 : 0; }
template <typename T, typename U> bool chmax(T &lhs, U rhs) { return lhs < rhs ? lhs = rhs, 1 : 0; }

#endif