#include <fstream>
using namespace std;

ifstream is("aib.in");
ofstream os("aib.out");

int n, m, a[100001];
int type;
int x, y;

void Update(int pos, int val);
int Query(int pos);
int BinarySearch(int val);

int main()
{
    is >> n >> m;
    for ( int i = 1; i <= n; ++i )
    {
        is >> x;
        Update(i, x);
    }

    for ( int i = 1; i <= m; ++i )
    {
        is >> type;
        if ( type == 2 )
            is >> y;
        else
            is >> x >> y;
        switch (type)
        {
            case 0 :
                Update(x, y);
                break;
            case 1 :
                os << Query(y) - Query(x - 1) << '\n';
                break;
            case 2 :
                os << BinarySearch(y) << '\n';
                break;
        }

    }

    is.close();
    os.close();
    return 0;
}

void Update(int pos, int val)
{
    for ( int i = pos; i <= n; i += i & -i )
        a[i] += val;
}

int Query(int pos)
{
    int s = 0;
    for ( int i = pos ; i; i -= i & -i )
        s += a[i];
    return s;
}

int BinarySearch(int val)
{
    int byte;
    for ( byte = 1; byte < n; byte <<= 1 );
    for ( int pos = 0; byte; byte >>= 1 )
        if ( pos + byte <= n && a[pos + byte] <= val )
        {
            pos += byte;
            val -= a[pos];
            if ( !val )
                return pos;
        }
    return -1;
}