#include <bits/stdc++.h>


using namespace std;

ifstream fin ("aib.in");
ofstream fout ("aib.out");

const int Nmax = 1e5 + 5;


int aib[Nmax]  , n , Q;


inline void Update(int p , int x)
{
    while(p <= n)
    {
        aib[p] += x;
        p += (p & (-p));
    }
}

inline int Sum(int p)
{
    int sum = 0;
    while(p >= 1)
    {
        sum += aib[p];
        p -= (p & (-p));
    }
    return sum;
}



int main()
{
    int x , p , L , R , poz , m , op;
    fin >> n >> Q;
    for(int i = 1 ; i <= n ; i++)
        fin >> x , Update(i , x);
    while(Q -- )
    {
        fin >> op;
        if(op == 0)
        {
            fin >> p >> x;
            Update(p , x);
        }
        else if(op == 1)
        {
            fin >> p >> x;
            fout << Sum(x) - Sum(p - 1) << "\n";
        }
        else
        {
            fin >> x;
            L = 1;
            R = n;
            poz = -1;
            while(L <= R)
            {
                m = (L + R) / 2;
                p = Sum(m);
                if(p == x)
                    poz = m , R = m - 1;
                else if(p < x)
                    L = m + 1;
                else R = m - 1;
            }
            fout << poz << "\n";
        }
    }
    fin.close();
    fout.close();
}