#include <fstream>

using namespace std;

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

const int NMAX = 100000 + 5;
const int INF = 0x3f3f3f3f;

int n, m;
int aib[NMAX];

int zeros(int x)
{
    return x ^ (x & (x - 1));
}

void update(int poz, int val)
{
    for (int i = poz; i <= n; i += zeros(i))
        aib[i] += val;
}

int query(int poz)
{
    int rez = 0;
    for (int i = poz; i; i -= zeros(i))
        rez += aib[i];
    return rez;
}

int sum(int st, int dr)
{
    return query(dr) - query(st - 1);
}

int bs(int total)
{
    int st = 1, dr = n, mijl, ans = INF;
    while (st <= dr)
    {
        mijl = (st + dr) / 2;
        if (query(mijl) == total)
        {
            return mijl;
        }
        else if (query(mijl) > total)
            dr = mijl - 1;
        else
            st = mijl + 1;
    }
    return -1;
}

void read()
{
    int x;
    fin >> n >> m;
    for (int i = 1; i <= n; ++i)
    {
        fin >> x;
        update(i, x);
    }
}

int main()
{
    int cod, a, b;

    read();
    while (m--)
    {
        fin >> cod >> a;
        if (cod != 2)
            fin >> b;

        if (cod == 0)
            update(a, b);
        else if (cod == 1)
            fout << sum(a, b) << '\n';
        else
            fout << bs(a) << '\n';
    }

    return 0;
}