#include <bits/stdc++.h>
#define ub(x) (x & (-x))
using namespace std;
ifstream fin("aib.in");
ofstream fout("aib.out");

constexpr int NMAX = 1e5 + 3;

int n, m, q, a, b, x;
int aib[NMAX];

void update(int x, int val)
{
    for(int i = x; i <= n; i += ub(i))
        aib[i] += val;
    return;
}

int query(int x)
{
    int ans = 0;
    for(int i = x; i > 0; i -= ub(i))
        ans += aib[i];
    return ans;
}

int sum(int x, int y)
{
    return query(y) - query(x - 1);
}

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

    for(int i = 1; i <= m; i ++)
    {
        fin >> q;
        if(q == 0)
            fin >> a >> b, update(a, b);
        else if(q == 1)
            fin >> a >> b, fout << sum(a, b) << '\n';
        else {
            fin >> a;
            int l = 1, r = n, poz = -1, mid;
            while(l <= r)
            {
                mid = (l + r) >> 1;
                if(sum(1, mid) == a){
                    poz = mid;
                    break;
                }

                if(sum(1, mid) > a)
                    r = mid - 1;
                else l = mid + 1;
            }

            fout << poz << '\n';
        }
    }
    return 0;
}