#include <bits/stdc++.h>

using namespace std;

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

void usain_bolt()
{
    ios::sync_with_stdio(false);
    fin.tie(0);
}

const int N = 1e5 + 5;

int fen[N];

void update(int node, int val)
{
    for(; node <= N - 5; node += node & (-node)) {
        fen[node] += val;
    }
}

int sum(int node)
{
    int sol = 0;
    for(; node > 0; node -= node & (-node)) {
        sol += fen[node];
    }
    return sol;
}

int main()
{
    usain_bolt();

    int n, q;

    fin >> n >> q;
    for(int i = 1; i <= n; ++i) {
        int x;

        fin >> x;
        update(i, x);
    }
    for(; q; --q) {
        int type;

        fin >> type;
        if(type == 0) {
            int pos, val;

            fin >> pos >> val;
            update(pos, val);
        }
        else if(type == 1) {
            int x, y;

            fin >> x >> y;
            fout << sum(y) - sum(x - 1) << "\n";
        }
        else {
            int val;

            fin >> val;
            int left = 1, right = n;
            while(left <= right) {
                int mid = (left + right) >> 1;
                int total = sum(mid);
                if(total == val) {
                    fout << mid << "\n";
                    break;
                }
                else if(total > val) right = mid - 1;
                else left = mid + 1;
            }
        }
    }
    return 0;
}