#include <bits/stdc++.h>
using std::cin;
using std::cout;
using std::endl;
using std::vector;
using std::string;
using ll = long long;
using vi = vector<ll>;
using vii = vector<vi>;
using pii = std::pair<ll,ll>;

#define ln "\n"
#define rep(i,j,k) for(ll i=ll(j); i<ll(k); i++)
#define REP(i,j,k) for(ll i=ll(j); i<=ll(k); i++)
#define per(i,j,k) for(ll i=ll(j); i>=ll(k); i--)
#define all(a) a.begin(), a.end()
#define pb emplace_back
#define mp std::make_pair

constexpr ll inf = (1ll<<60);

int main(){
    ll N,Q; cin >> N >> Q;
    vi C(N);
    rep(i,0,N) cin >> C[i];
    while(Q--){
        ll l,d; cin >> l >> d;
        C[l-1] += d;
        vi memC = C;
        ll ans = 0;
        std::set<ll> remain;
        remain.insert(inf);
        rep(i,0,N){
            if(C[i]) remain.insert(i);
        }
        rep(i,0,N){
            if(remain.count(i)) remain.erase(i);
            if(C[i]%3 == 0){
                ans += C[i]/3;
                C[i] = 0;
                continue;
            }
            if(C[i]%3 == 1){
                if(C[i] == 1){
                    C[i] = 0;
                    continue;
                }
                ans += C[i]/3-1;
                C[i] = 4;
            }
            if(C[i]%3 == 2){
                ans += C[i]/3;
                C[i] = 2;
            }
            rep(j,0,C[i]/2){
                ll idx = -1;
                ll max = -1;
                for(auto el: remain){
                    if(el > 2*i) break;
                    if(max < C[el]){
                        max = C[el];
                        idx = el;
                    }
                }
                if(idx == -1) break;
                C[idx]--;
                ans++;
                if(C[idx] == 0) remain.erase(idx);
            }
            C[i] = 0;
        }
        cout << ans << ln;
        C = memC;
    }
}