#include <fstream>
using namespace std;
ifstream fin ("aib.in");
ofstream fout ("aib.out");
int n,m,i,x,a,b,sum,s,ch,st,dr,mij,v[100005],aib[100005];
void update (int i)
{
    for (; i<=n; i+=(i&-i))
        aib[i]+=x;
}
int query (int i)
{
    s=0;
    for (; i>0; i-=(i&-i))
        s=s+aib[i];
    return s;
}
int main()
{
    fin>>n>>m;
    for (i=1; i<=n; i++)
    {
        fin>>x;
        update (i);
    }
    for (i=1; i<=m; i++)
    {
        fin>>ch;
        if (ch==0)
        {
            fin>>a>>b;
            x=b;
            update (a);
        }
        if (ch==1)
        {
            fin>>a>>b;
            fout<<query (b)-query (a-1)<<"\n";
        }
        if (ch==2)
        {
            fin>>sum;
            st=1;
            dr=n;
            while (st<=dr)
            {
                mij=(st+dr)/2;
                if (query (mij)<sum)
                    st=mij+1;
                else
                    dr=mij-1;
            }
            if (query (st)==sum)
                fout<<st<<"\n";
            else
                fout<<"-1\n";
        }
    }
    return 0;
}