//code by Emissary
#include<bits/stdc++.h>

#define fi first
#define se second
#define vc vector
#define db double
#define ll long long
#define mk make_pair
#define pb push_back
#define PI pair<int,int>
#define ull unsigned long long
#define err cerr << "   -_-   " << endl
#define debug cerr << " ------------------- " << endl

#define input(x) freopen(#x".in","r",stdin)
#define output(x) freopen(#x".out","w",stdout)

#define NO puts("No")
#define YES puts("Yes")

//#define int long long

using namespace std;

namespace IO{
	inline int read(){
		int X=0, W=0; char ch=getchar();
		while(!isdigit(ch)) W|=ch=='-', ch=getchar();
		while(isdigit(ch)) X=(X<<1)+(X<<3)+(ch^48), ch=getchar();
		return W?-X:X;
	}
	inline void write(int x){
		if(x<0) x=-x, putchar('-');
		if(x>9) write(x/10);
		putchar(x%10+'0');
	}
	inline void sprint(int x){write(x), putchar(32);}
	inline void eprint(int x){write(x), putchar(10);}
}using namespace IO;

const int MAXN = 2e5+5;

int n, m, q;

ll d[MAXN], v[MAXN], c[MAXN]; 

struct Tree{
	ll mch;
	ll L, R;
}tree[MAXN<<2];

inline void pushup(int p){
	tree[p].mch=tree[p<<1].mch+tree[p<<1|1].mch+min(tree[p<<1|1].R,tree[p<<1].L);
	ll c=min(tree[p<<1|1].R,tree[p<<1].L); tree[p].L=tree[p<<1].L+tree[p<<1|1].L-c; tree[p].R=tree[p<<1].R+tree[p<<1|1].R-c;
}

inline void build(int p, int l, int r){
	if(l==r) return tree[p].mch=min(v[l],c[l]), tree[p].L=max(c[l]-v[l],0ll), tree[p].R=max(0ll,v[l]-c[l]), void();
	int mid=(l+r)>>1;
	build(p<<1,l,mid); build(p<<1|1,mid+1,r);
	return pushup(p);
}

inline void upd(int p, int l, int r, int pos){
	if(l==r) return tree[p].mch=min(v[l],c[l]), tree[p].L=max(c[l]-v[l],0ll), tree[p].R=max(0ll,v[l]-c[l]), void();
	int mid=(l+r)>>1;
	pos<=mid?upd(p<<1,l,mid,pos):upd(p<<1|1,mid+1,r,pos);
	return pushup(p);
}

signed main(){
	n=read(), q=read();
	for(int i=1;i<=n;++i) d[i]=read(), v[i]=d[i]/2;
	for(int i=1;i<=n;++i) if(d[i]%2==1) c[i/2+1]++;
	build(1,1,n);
	while(q--){
		int l, t;
		l=read(), t=read();
		if(d[l]%2==1) c[l/2+1]--; 
		d[l]+=t; v[l]=d[l]/2;
		if(d[l]%2==1) c[l/2+1]++;
		upd(1,1,n,l/2+1); upd(1,1,n,l);
		eprint(tree[1].mch+tree[1].R*2/3);
	}
	return 0;
}