///yl/hs/bx/yl
#include<bits/stdc++.h>
#define fep(i,l,r) for(int i=l;i<=r;++i)
#define feb(i,r,l) for(int i=r;i>=l;--i)
#define For(i,u) for(int i=head[u];i;i=e[i].nxt)
#define LL long long
// #define int long long
#define ld long double
#define pr pair<int,int>
#define mpr make_pair
using namespace std;

const int N = 4e5+5,mod = 1e9+7;
inline int read()
{
   int s=0,w=1; char ch=getchar();
   while(!(ch>='0'&&ch<='9')) {if(ch=='-') w=-1; ch=getchar();}
   while(  ch>='0'&&ch<='9')  {s=(s<<1)+(s<<3)+ch-'0'; ch=getchar();}
   return s*w;
}
inline int Mod(int x) {return x>=mod?x-mod:x;}
inline void addmod(int &x,int y) {x=Mod(x+y);}

namespace starrylasky
{
    int n,Q,c[N];
    struct SGT
    {
        #define lson u<<1
        #define rson u<<1|1
        #define mid (l+r>>1)
        LL sl[N<<2],sr[N<<2],sd[N<<2];
        inline void pushup(int u)
        {
            int res=min(sl[lson],sr[rson]);
            sd[u]=sd[lson]+sd[rson]+res;
            sl[u]=sl[lson]+sl[rson]-res;
            sr[u]=sr[lson]+sr[rson]-res;
        }

        inline void work(int u)
        {
            int res=min(sl[u],sr[u]);
            sl[u]-=res; sr[u]-=res; sd[u]+=res;// cerr<<sl[u]<<" "<<sr[u]<<" "<<sd[u]<<"\n";
        }

        inline void update(int u,int l,int r,int pos)
        {
            if(l==r) return sl[u]=c[l]&1,sr[u]=(l&1?c[l+1>>1]>>1:0),sd[u]=0,work(u);
            if(mid>=pos) update(lson,l,mid,pos);
            else update(rson,mid+1,r,pos);
            pushup(u);
        }
    }sgt;

    inline void Main()
    {
        n=read(),Q=read();
        fep(i,1,n) c[i]=read();
        fep(i,1,2*n) sgt.update(1,1,2*n,i);
        fep(i,1,Q)
        {
            int p=read(),v=read(); c[p]+=v;
            sgt.update(1,1,n,p); sgt.update(1,1,n,2*p-1);
            printf("%lld\n",sgt.sd[1]+2*sgt.sr[1]/3);
        }
    }
}

signed main()
{
    int _T=1;
    while(_T--) starrylasky::Main();
    return 0;
}