#include <bits/stdc++.h>

#define NMAX 100005
using namespace std;
ifstream fin("aib.in");
ofstream fout("aib.out");
int n, m, v[2 * NMAX];

void read();

void solve();

int lsb(int pos) {
    return pos & -pos;
}

void update(int pos, int val) {
    while (pos <= n) {
        v[pos] += val;
        pos += lsb(pos);
    }
}

int query(int pos) {
    int s = 0;
    while (pos > 0) {
        s += v[pos];
        pos -= lsb(pos);
    }
    return s;
}

int q3(int a) {
    int p = 0, k = 0;
    while ((1 << p) < n)
        p++;
    int crtSum = 0;
    while (p >= 0) {
        if (k + (1 << p) <= n) {
            if (crtSum + v[k + (1 << p)] == a)
                return k + (1 << p);
            if (crtSum + v[k + (1 << p)] < a) {
                k += (1 << p);
                crtSum += v[k];
            }
        }
        p--;
    }
    return -1;
}

int main() {
    read();
    solve();
    return 0;
}

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

void solve() {
    int op, a, b;
    for (int q = 1; q <= m; ++q) {
        fin >> op >> a;
        if (op != 2)
            fin >> b;
        if (op == 0)
            update(a, b);
        else if (op == 1)
            fout << query(b) - query(a - 1) << '\n';
        else fout << q3(a) << '\n';
    }
}