#include <iostream>
#include <fstream>
using namespace std;
ifstream fin("aib.in");
ofstream fout("aib.out");
int n,aib[100005],m;
void adun(int x,int val)
{
    for(int i=x;i<=n;i+=(i&(-i)))
    {
        aib[i]+=val;
    }
}
int suma(int x)
{
    int sum=0,i;
    for(int i=x;i>=1;i-=(i&(-i)))
        sum+=aib[i];
        return sum;
}
int main()
{
    fin>>n>>m;
    int nr;
    for(int i=1;i<=n;i++)
        {fin>>nr; adun(i,nr);}
    for(int i=1;i<=m;i++)
    {
        short cer;
        fin>>cer;
        if(cer==0)
        {
            int poz1,nr1;
            fin>>poz1>>nr1;
            adun(poz1,nr1);
        }
        if(cer==1)
        {
            int x1,x2;
            fin>>x1>>x2;
            fout<<suma(x2)-suma(x1-1)<<'\n';
        }
        if(cer==2)
        {
            int st=1,dr=n,v;
            fin>>v;
            int mij=(st+dr)/2;
            while(v!=suma(mij))
            {
                //cout<<mij<<" ";
                if(v<suma(mij)) {dr=mij-1; mij=(st+dr)/2;}
                else if(v>suma(mij)) {st=mij+1; mij=(st+dr)/2;}
            }
            fout<<mij<<'\n';

        }
    }

    return 0;
}