#include<bits/stdc++.h>
using namespace std;
inline int read()
{
	int n=0,f=1,ch=getchar();
	while(ch<'0'||ch>'9')
	{
		if(ch=='-')f=-1;
		ch=getchar();
	}
	while(ch>='0'&&ch<='9')
	{
		n=n*10+ch-'0';
		ch=getchar();
	}
	return n*f;
}
struct tree
{
	int l,r,het,maxn;
}a[800004];
int ys[200005],f[200005];
void build(int l,int r,int k)
{
	a[k].l=l;
	a[k].r=r;
	if(l==r)
	{
		a[k].het=f[l];
		a[k].maxn=max(0,f[l]);
		return;
	}
	build(l,(l+r)>>1,k<<1);
	build(((l+r)>>1)+1,r,k<<1|1);
	a[k].het=a[k<<1].het+a[k<<1|1].het;
	a[k].maxn=max(a[k<<1].maxn,a[k<<1].het+a[k<<1|1].maxn);
}
void change(int x,int k,int y)
{
	if(a[k].l==a[k].r)
	{
		a[k].het=max(y,0);
		a[k].maxn=y;
		return;
	}
	if(x<=a[k<<1].r)change(x,k<<1,y);
	else change(x,k<<1|1,y);
	a[k].het=a[k<<1].het+a[k<<1|1].het;
	a[k].maxn=max(a[k<<1].maxn,a[k<<1].het+a[k<<1|1].maxn);
}
int main()
{
	int n,q,zs=0;
	n=read();
	q=read();
	for(int i=1;i<=n;i++)
	{
		ys[i]=read();
		zs+=ys[i]/2;
		f[i]+=ys[i]/2;
		f[(i+1)/2]-=(ys[i]%2);
	}
	int x,y;
	for(int i=1;i<=q;i++)
	{
		x=read();
		y=read();
		f[x]-=ys[x]/2;
		f[(x+1)/2]+=(ys[x]%2);
		zs-=ys[x]/2;
		ys[x]+=y;
		f[x]+=ys[x]/2;
		f[(x+1)/2]-=(ys[x]%2);
		zs+=ys[x]/2;
		change(x,1,f[x]);
		change((x+1)/2,1,f[(x+1)/2]);
		printf("%d\n",zs-(a[1].maxn+2)/3);
	}
}