// AIB.cpp : This file contains the 'main' function. Program execution begins and ends there.
//

#include <fstream>
#include <iostream>
using namespace std;
const int NMAX = 100010;
int aib[NMAX], N, M;
ifstream fin("aib.in");
ofstream fout("aib.out");
int lsb(int x)
{
    return x & (-x);
}
void update(int i, int val)
{
    while (i <= N)
    {
        aib[i] += val;
        i += lsb(i);
    }
}
int sum(int i)
{
    if (lsb(i) == i)
        return aib[i];
    else
        return aib[i] + sum(i - lsb(i));
}
int bs(int x, int l, int r)
{
    if (r <= l + 1)
    {
        if (sum(l) == x)
            return l;
        if (sum(r) == x)
            return r;
        return -1;
    }
    int mid = (l + r) >> 1;
    int s = sum(mid);
    if (s == x)
        return mid;
    if (x < s)
        return bs(x, l, mid);
    return bs(x, mid + 1, r);
}
int main()
{
    fin >> N >> M;
    int x;
    for (int i = 1; i <= N; i++)
    {
        fin >> x;
        update(i, x);
    }
    int tip, a, b;
    while (M--)
    {
        fin >> tip >> a;
        switch (tip)
        {
        case 0:
        {
            fin >> b;
            update(a, b);
            break;
        }
        case 1:
        {
            fin >> b;
            fout << sum(b) - sum(a - 1) << "\n";
            break;
        }
        case 2:
        {
            fout << bs(a, 1, N) << "\n";
            break;
        }
        }
    }
    return 0;
}