#include <bits/stdc++.h>
using namespace std;
#if __has_include(<atcoder/all>)
#include <atcoder/all>
using namespace atcoder;
#endif
using ll = long long;
using ld = long double;
using ull = unsigned long long;
#define endl "\n"
typedef pair<int, int> Pii;
#define REP(i, n) for (int i = 0; i < (n); ++i)
#define REP3(i, m, n) for (int i = (m); (i) < int(n); ++ (i))
#define rep(i,a,b) for(int i=(int)(a);i<(int)(b);i++)
#define ALL(x) begin(x), end(x)
#define rrep(i,a,b) for(int i=a;i>=b;i--)
#define fore(i,a) for(auto &i:a)
#define all(s) (s).begin(),(s).end()
#define drep2(i, m, n) for (int i = (m)-1; i >= (n); --i)
#define drep(i, n) drep2(i, n, 0)
#define rever(vec) reverse(vec.begin(), vec.end())
#define sor(vec) sort(vec.begin(), vec.end())
#define fi first
#define FOR_(n) for (ll _ = 0; (_) < (ll)(n); ++(_))
#define FOR(i, n) for (ll i = 0; (i) < (ll)(n); ++(i))
#define se second
#define pb push_back
#define P pair<ll,ll>
#define PQminll priority_queue<ll, vector<ll>, greater<ll>>
#define PQmaxll priority_queue<ll,vector<ll>,less<ll>>
#define PQminP priority_queue<P, vector<P>, greater<P>>
#define PQmaxP priority_queue<P,vector<P>,less<P>>
#define NP next_permutation
//const ll mod = 1000000009;
//const ll mod = 998244353;
const ll mod = 1000000007;
const ll inf = 4100000000000000000ll;
const ld eps = ld(0.00000000001);
static const long double pi = 3.141592653589793;
template<class T>void vcin(vector<T> &n){for(int i=0;i<int(n.size());i++) cin>>n[i];}
template<class T,class K>void vcin(vector<T> &n,vector<K> &m){for(int i=0;i<int(n.size());i++) cin>>n[i]>>m[i];}
template<class T>void vcout(vector<T> &n){for(int i=0;i<int(n.size());i++){cout<<n[i]<<" ";}cout<<endl;}
template<class T>void vcin(vector<vector<T>> &n){for(int i=0;i<int(n.size());i++){for(int j=0;j<int(n[i].size());j++){cin>>n[i][j];}}}
template<class T>void vcout(vector<vector<T>> &n){for(int i=0;i<int(n.size());i++){for(int j=0;j<int(n[i].size());j++){cout<<n[i][j]<<" ";}cout<<endl;}cout<<endl;}
void yes(bool a){cout<<(a?"yes":"no")<<endl;}
void YES(bool a){cout<<(a?"YES":"NO")<<endl;}
void Yes(bool a){cout<<(a?"Yes":"No")<<endl;}
void possible(bool a){ cout<<(a?"possible":"impossible")<<endl; }
void Possible(bool a){ cout<<(a?"Possible":"Impossible")<<endl; }
void POSSIBLE(bool a){ cout<<(a?"POSSIBLE":"IMPOSSIBLE")<<endl; }
#define FOR_R(i, n) for (ll i = (ll)(n)-1; (i) >= 0; --(i))
template<class T>auto min(const T& a){ return *min_element(all(a)); }
template<class T>auto max(const T& a){ return *max_element(all(a)); }
template<class T,class F>void print(pair<T,F> a){cout<<a.fi<<" "<<a.se<<endl;}
template<class T>bool chmax(T &a,const T b) { if (a<b) { a=b; return 1; } return 0;}
template<class T>bool chmin(T &a,const T b) { if (b<a) { a=b; return 1; } return 0;}
template<class T> void ifmin(T t,T u){if(t>u){cout<<-1<<endl;}else{cout<<t<<endl;}}
template<class T> void ifmax(T t,T u){if(t>u){cout<<-1<<endl;}else{cout<<t<<endl;}}
ll fastgcd(ll u,ll v){ll shl=0;while(u&&v&&u!=v){bool eu=!(u&1);bool ev=!(v&1);if(eu&&ev){++shl;u>>=1;v>>=1;}else if(eu&&!ev){u>>=1;}else if(!eu&&ev){v>>=1;}else if(u>=v){u=(u-v)>>1;}else{ll tmp=u;u=(v-u)>>1;v=tmp;}}return !u?v<<shl:u<<shl;}
ll modPow(ll a, ll n, ll mod) { if(mod==1) return 0;ll ret = 1; ll p = a % mod; while (n) { if (n & 1) ret = ret * p % mod; p = p * p % mod; n >>= 1; } return ret; }
vector<ll> divisor(ll x){ vector<ll> ans; for(ll i = 1; i * i <= x; i++){ if(x % i == 0) {ans.push_back(i); if(i*i!=x){ ans.push_back(x / ans[i]);}}}sor(ans); return ans; }
ll pop(ll x){return __builtin_popcountll(x);}
ll poplong(ll x){ll y=-1;while(x){x/=2;y++;}return y;}
P hyou(P a){ll x=fastgcd(abs(a.fi),abs(a.se));a.fi/=x;a.se/=x;if(a.se<0){a.fi*=-1;a.se*=-1;}return a;}
P Pplus(P a,P b){ return hyou({a.fi*b.se+b.fi*a.se,a.se*b.se});}
P Ptimes(P a,ll b){ return hyou({a.fi*b,a.se});}
P Ptimes(P a,P b){ return hyou({a.fi*b.fi,a.se*b.se});}
P Pminus(P a,P b){ return hyou({a.fi*b.se-b.fi*a.se,a.se*b.se});}
P Pgyaku(P a){ return hyou({a.se,a.fi});}
template<class T>
struct Sum{
  vector<T> data;
  Sum(const vector<T>& v):data(v.size()+1){
    for(ll i=0;i<v.size();i++) data[i+1]=data[i]+v[i];
  }
  T get(ll l,ll r) const {
    return data[r]-data[l];
  }
};
template<class T>
struct Sum2{
  vector<vector<T>> data;
  Sum2(const vector<vector<T>> &v):data(v.size()+1,vector<T>(v[0].size()+1)){
    for(int i=0;i<v.size();i++) for(int j=0;j<v[i].size();j++) data[i+1][j+1]=data[i][j+1]+v[i][j];
    for(int i=0;i<v.size();i++) for(int j=0;j<v[i].size();j++) data[i+1][j+1]+=data[i+1][j];
  }
  T get(ll x1,ll y1,ll x2,ll y2) const {
    return data[x2][y2]+data[x1][y1]-data[x1][y2]-data[x2][y1];
  }
};
 
void cincout(){
  ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
  cout<< fixed << setprecision(15);
}
struct Segtree{
  vector<ll> node,lazy;
  ll n;
  Segtree(vector<ll> a){
    ll N=a.size();
    n=1;
    while(n<N) n*=2;
    node.resize(2*n);
    lazy.resize(2*n);
    for(int i=0;i<a.size();i++) node[i+n]=a[i];
    for(int i=n-1;i>=1;i--) node[i]=min(node[2*i],node[2*i+1]);
  }
  void eval(ll k){
    if(lazy[k]==0) return;
    if(k<=n-1){
      lazy[2*k]=lazy[2*k]+lazy[k];
      lazy[2*k+1]=lazy[2*k+1]+lazy[k];
    }
    node[k]=node[k]+lazy[k];
    lazy[k]=0;
  }
  void add(int l,int r,int a,int b,int k,int x){
    eval(k);
    if(r<=a||b<=l) return;
    if(l<=a&&b<=r){
      lazy[k]+=x;
      eval(k);
    }
    else{
      add(l,r,a,(a+b)/2,2*k,x);
      add(l,r,(a+b)/2,b,2*k+1,x);
      node[k]=min(node[2*k],node[2*k+1]);
    }
  }
  void add(int l,int r,int x){
    add(l,r,0,n,1,x);
  }
  ll get(int l,int r,int a,int b,int k){
    eval(k);
    if(r<=a||b<=l) return inf;
    if(l<=a&&b<=r){
      return node[k];
    }
    else{
      return min(get(l,r,a,(a+b)/2,2*k),get(l,r,(a+b)/2,b,2*k+1));
    }
  }
  ll get(int l,int r){
    return get(l,r,0,n,1);
  }
};
int main() {
  cincout();
  ll n,q;
  cin>>n>>q;
  vector<ll> a(n+1);
  for(int i=1;i<=n;i++) cin>>a[i];
  if(n<=2000&&q<=2000){
    for(int _=0;_<q;_++){
    ll x,d;
    cin>>x>>d;
    a[x]+=d;
    ll ok=0,ng=0;
    for(int i=1;i<=n;i++) ng+=a[i]/2;
    ng++;
    while(abs(ok-ng)>1){
      ll m=(ok+ng)/2;
      ll k=m;
      for(int i=n;i>=0;i--){
        if(k>=a[i]/2){
          b[i]=a[i]-(a[i]/2)*2;
          c[i]=a[i]/2;
          k-=a[i]/2;
        }
        else{
          b[i]=a[i]-2*k;
          c[i]=k;
          k=0;
        }
      }
      ll p=0;
      ll q=0;
      bool check=true;
      while(q<=n){
        while(c[q]){
          if(p>q*2-1||p>n){
            check=false;
            break;
          }
          ll use=min(c[q],b[p]);
          c[q]-=use;
          b[p]-=use;
          if(b[p]==0) p++;
        }
        if(!check) break;
        q++;
      }
      if(check) ok=m;
      else ng=m;
    }
    cout<<ok<<endl;
  }
    return 0;
  }
  vector<ll> b(n+1),c(n+1);
  for(int _=0;_<1;_++){
    ll x,d;
    cin>>x>>d;
    a[x]+=d;
    ll ok=0,ng=0;
    for(int i=1;i<=n;i++) ng+=a[i]/2;
    ng++;
    while(abs(ok-ng)>1){
      ll m=(ok+ng)/2;
      ll k=m;
      for(int i=n;i>=0;i--){
        if(k>=a[i]/2){
          b[i]=a[i]-(a[i]/2)*2;
          c[i]=a[i]/2;
          k-=a[i]/2;
        }
        else{
          b[i]=a[i]-2*k;
          c[i]=k;
          k=0;
        }
      }
      ll p=0;
      ll q=0;
      bool check=true;
      while(q<=n){
        while(c[q]){
          if(p>q*2-1||p>n){
            check=false;
            break;
          }
          ll use=min(c[q],b[p]);
          c[q]-=use;
          b[p]-=use;
          if(b[p]==0) p++;
        }
        if(!check) break;
        q++;
      }
      if(check) ok=m;
      else ng=m;
    }
    cout<<ok<<endl;
    while(true){
      ll m=ok;
      ll k=m;
      for(int i=n;i>=0;i--){
        if(k>=a[i]/2){
          b[i]=a[i]-(a[i]/2)*2;
          c[i]=a[i]/2;
          k-=a[i]/2;
        }
        else{
          b[i]=a[i]-2*k;
          c[i]=k;
          k=0;
        }
      }
      break;
    }
  }
  set<ll> ps,nb;
  for(int i=0;i<=n;i++) if(c[i]) ps.insert(i);
  for(int i=0;i<=n;i++) if(b[i]>=2) nb.insert(i);
  bool ok=true;
  vector<ll> d(2*n+1);
  for(int i=0;i<=n;i++) d[i]+=b[i];
  for(int i=0;i<=n;i++) d[2*i-1]-=c[i];
  for(int i=1;i<=2*n;i++) d[i]+=d[i-1];
  Segtree seg(d);
 /* for(auto e:d) cout<<e<<" ";
  cout<<endl;
  for(int i=0;i<2*n+1;i++) cout<<seg.get(i,i+1)<<" ";
    cout<<endl;*/
  ll sumc=0;
  for(auto e:c) sumc+=e;
  auto badd = [&](int x){
    b[x]++;
    seg.add(x,2*n+1,1);
    if(b[x]>=2) nb.insert(x);
  };
  auto berase = [&](int x){
    if(b[x]){
      b[x]--;
      seg.add(x,2*n+1,-1);
      if(b[x]<=1) nb.erase(x);
    }
    else{
      c[x]--;
      sumc--;
      b[x]++;
      seg.add(x,2*n+1,1);
      seg.add(2*x-1,2*n+1,1);
      if(c[x]==0) ps.erase(x);
      if(b[x]>=2) nb.insert(x);
    }
  };
  auto padd = [&](){
    ok=true;
    if(nb.size()==0){
      ok=false;
      return;
    }
    auto itr=nb.end();
    itr--;
    ll v=(*itr);
   // cout<<"V"<<" "<<v<<endl;
   // for(int i=0;i<2*n+1;i++) cout<<seg.get(i,i+1)<<" ";
   // cout<<endl;
    seg.add(v,2*n+1,-2);
    seg.add(2*v-1,2*n+1,-1);
    if(seg.get(0,2*n+1)<0){
      seg.add(v,2*n+1,2);
      seg.add(2*v-1,2*n+1,1);
      ok=false;
      return;
    }
    if(c[v]==0) ps.insert(v);
    c[v]++;
    sumc++;
    b[v]-=2;
    if(b[v]<2){
      nb.erase(v);
    }
  };
  auto perase = [&](){
    if(ps.size()==0) return;
    auto itr=ps.begin();
    ll v=(*itr);
    b[v]+=2;
    c[v]--;
    sumc--;
    seg.add(v,2*n+1,2);
    seg.add(2*v-1,2*n+1,1);
    if(b[v]>=2) nb.insert(v);
    if(c[v]==0) ps.erase(v);
  };
  for(int _=0;_<q-1;_++){
    ll x,d;
    cin>>x>>d;
    if(d==1){
   /*   for(auto e:b) cout<<e<<" ";
      cout<<endl;
      for(auto e:c) cout<<e<<" ";
      cout<<endl;*/
      badd(x);
    /*  for(auto e:b) cout<<e<<" ";
      cout<<endl;
      for(auto e:c) cout<<e<<" ";
      cout<<endl;  */
      perase();
    /*  for(auto e:b) cout<<e<<" ";
      cout<<endl;
      for(auto e:c) cout<<e<<" ";
      cout<<endl; */
      ok=true;
      while(ok){
     //   cout<<"ADD"<<" "<<nb.size()<<endl;
        padd();
      }
    /*  for(auto e:b) cout<<e<<" ";
      cout<<endl;
      for(auto e:c) cout<<e<<" ";
      cout<<endl; */
    }
    else{
      berase(x);
      perase();
      ok=true;
      while(ok){
        padd();
      }
    }
    cout<<sumc<<endl;
  }
}

answer.code: In function ‘int main()’:
answer.code:167:11: error: ‘b’ was not declared in this scope
  167 |           b[i]=a[i]-(a[i]/2)*2;
      |           ^
answer.code:168:11: error: ‘c’ was not declared in this scope
  168 |           c[i]=a[i]/2;
      |           ^
answer.code:172:11: error: ‘b’ was not declared in this scope
  172 |           b[i]=a[i]-2*k;
      |           ^
answer.code:173:11: error: ‘c’ was not declared in this scope
  173 |           c[i]=k;
      |           ^
answer.code:181:15: error: ‘c’ was not declared in this scope
  181 |         while(c[q]){
      |               ^
answer.code:186:27: error: ‘b’ was not declared in this scope
  186 |           ll use=min(c[q],b[p]);
      |                           ^