#include <bits/stdc++.h>

using namespace std;
ifstream fin("aib.in");
ofstream fout("aib.out");
int n, v[100005], aib[100005], cer, x, y, nrq, pw2;
void update(int poz, int val)
{
    for(int i = poz; i <= n; i += i & (-i))
            aib[i] += val;
}
int sum(int poz)
{
    int sum = 0;
    for(int i = poz; i > 0; i -= i & (-i))
        sum += aib[i];
    return sum;
}
int findd(int cauta)
{
    int ls = 1;
    int ld = n;

    while(ls <= ld)
    {
        int mij = (ls + ld) >> 1;
        if(cauta == sum(mij))
        {
            return mij;
        }
        if(cauta > sum(mij))
        {
            ls = mij + 1;
        }
        else
        {
            ld = mij - 1;
        }
    }
    return -1;
}
int main()
{
    fin >> n >> nrq;
    for(pw2 = 1; pw2 <= n; pw2 <<= 1);
    pw2 >>= 1;
    for(int i = 1; i <= n; ++ i)
    {
        fin >> v[i];
        update(i, v[i]);
    }
    while(nrq--)
    {
        fin >> cer >> x;
        if(cer == 0)
        {
            fin >> y;
            update(x, y);
        } else if(cer == 1) {
            fin >> y;
            fout << sum(y) - sum(x - 1) << '\n';
        } else if(cer == 2) {
            fout << findd(x) << '\n';

        }
    }
    return 0;
}