#include <iostream>
#include <vector>
#include <fstream>
#include <algorithm>

#define ll long long
#define pb push_back

using namespace std;

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

const int NLIM = 1e5 + 10;

int N, M;
int BIT[NLIM];


void update( int i, int add )
{
    while( i <= N )
    {
        BIT[i] += add;
        i += i & ( -i );
    }
}

int get( int i )
{
    int ret = 0;
    while( i )
    {
        ret += BIT[i];
        i -= i & ( -i );
    }

    return ret;
}


int main()
{
    fin >> N >> M;
    for( int i = 1; i <= N; ++i )
    {
        int x;
        fin >> x;
        update( i, x );
    }


    while( M-- )
    {
        int t;
        fin >> t;

        if( t == 0 )
        {
            int a, b;
            fin >> a >> b;
            update( a, b );
        }
        else if( t == 1 )
        {
            int a, b;
            fin >> a >> b;
            fout << get( b ) - get( a - 1 ) << "\n";
        }
        else
        {
            int x;
            fin >> x;

            int l = 0;
            int r = N - 1;

            while( l <= r )
            {
                int m = l + ( r - l ) / 2;

                if( get( m ) >= x )
                    r = m - 1;
                else
                    l = m + 1;
            }
            if( get( l ) == x && l > 0 )
                fout << l << "\n";
            else
                fout << -1 << "\n";
        }
    }

    return 0;
}