#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

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;
        ll ans = 0;
        vi A(N), B(N);
        rep(i,0,N){
            A[i] = C[i]/3;
            B[i] = C[i]%3;
            ans += A[i];
        }
        ll left = 0;
        rep(i,0,N){
            if(B[i] == 2){
                for(; left<=std::min(N,i*2); left++){
                    if(B[left] == 1){
                        ans++;
                        B[left] = 0;
                        break;
                    }
                }
            }
        }
        cout << ans << ln;
    }
}