#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;
        ll ans = 0;
        vi sum1(N+1), sum2(N+1);
        rep(i,0,N){
            sum1[i+1] = sum1[i]+C[i]/2;
            sum2[i+1] = sum2[i]+C[i];
        }
        REP(i,1,N){
            ans = std::min(ans, sum2[std::min(i*2-1, N)]/3-sum1[i]);
        }
        ans += sum1[N];
        cout << ans << ln;
    }
}