#include <bits/stdc++.h>

using namespace std;

class FenwickTree
{
    int _n;
    vector <int> a;
    int lsb(int i)
    {
        return i & (-i);
    }

public:

    FenwickTree(int n)
    {
        _n = n;
        a.resize(n + 1);
    }

    void update(int pos, int val)
    {
        for(int i = pos; i <= _n; i += lsb(i))
            a[i] += val;
    }

    int query(int pos)
    {
        int sum = 0;
        for(int i = pos; i >= 1; i -= lsb(i))
            sum += a[i];
        return sum;
    }

    int binarySearch(int x)
    {
        int pas = 1 << 17, sum = 0, r = 0, last = -1;
        while(pas)
        {
            if(r + pas <= _n)
            {
                if(sum + a[r + pas] < x)
                {
                    sum += a[r + pas];
                    r += pas;
                }
                else if(sum + a[r + pas] == x)
                    last = r + pas;
            }
            pas >>= 1;
        }
        return last;
    }
};

int main()
{
    ios_base :: sync_with_stdio(0);
    cin.tie(0);

    freopen("aib.in", "r", stdin);
    freopen("aib.out", "w", stdout);

    int n, m;
    cin >> n >> m;

    FenwickTree aib(n);
    for(int i = 1; i <= n; i ++)
    {
        int x;
        cin >> x;
        aib.update(i, x);
    }

    for(int i = 1; i <= m; i ++)
    {
        int op;
        cin >> op;
        if(op == 0)
        {
            int a, b;
            cin >> a >> b;
            aib.update(a, b);
        }
        else if(op == 1)
        {
            int a, b;
            cin >> a >> b;
            cout << aib.query(b) - aib.query(a - 1) << "\n";
        }
        else
        {
            int a;
            cin >> a;
            cout << aib.binarySearch(a) << "\n";
        }
    }
    return 0;
}