#include <bits/stdc++.h>
using namespace std;

template <class T> class AIB
{
private:
	T* tree, lung;
	T sum_part(int poz)
	{
		T rez = 0;

		while (poz)
		{
			rez += tree[poz];
			poz -= poz & -poz;
		}

		return rez;
	}
public:
	AIB(int lungime)
	{
		lung = lungime;
		tree = new T[lung + 1]();
	}
	~AIB()
	{
		delete[] tree;
	}
	void add(int poz, T value)
	{
		while (poz <= lung)
		{
			tree[poz] += value;
			poz += poz & -poz;
		}
	}
	T sum(int st, int dr)
	{
		return sum_part(dr) - sum_part(st - 1);
	}
};

int n, q;
ifstream fin("aib.in");
ofstream fout("aib.out");

int main()
{
	fin >> n >> q;
	AIB <int> aib(n);

	for (int i = 1, val; i <= n; i++)
	{
		fin >> val;
		aib.add(i, val);
	}

	for (int t, a, b; q; q--)
	{
		fin >> t >> a;
		if (t != 2)
			fin >> b;

		switch (t)
		{
		case 0: aib.add(a, b); break;
		case 1: fout << aib.sum(a, b) << '\n'; break;
		case 2:
			int poz = 0;
			for (int p = n; p; p /= 2)
				while (poz + p <= n && aib.sum(1, poz + p) < a)
					poz += p;

			if (poz < n && aib.sum(1, poz + 1) == a)
				fout << poz + 1 << '\n';
			else
				fout << "-1\n";
		}
	}

	return 0;
}