#include <fstream>
#include <vector>

using namespace std;

ifstream cin("aib.in");
ofstream cout("aib.out");

int n, m;
class FenwickTree {
    vector<int> tree;
    int size;
    void update_(int pos, int val) {
        for (int i = pos ; i <= n ; i += i & -i) {
            tree[i] += val;
        }
    }
    int query_(int pos) {
        int ans = 0;
        for (int i = pos ; i > 0 ; i -= i & -i) {
            ans += tree[i];
        }
        return ans;
    }
public:
    FenwickTree(int size) {
        this->size = size;
        tree.assign(size + 2, 0);
    }
    void update(int pos, int val) {
        update_(pos, val);
    }
    int query(int query_left, int query_right) {
        return query_(query_right) - query_(query_left - 1);
    }
    int exact_sum_position(int sum) {
        int ans_idx = 0, current_sum = 0;
        for (int i = 1 << 30 ; i > 0 ; i >>= 1) {
            if (ans_idx + i <= n && current_sum + tree[ans_idx + i] < sum) {
                ans_idx += i;
                current_sum += tree[ans_idx];
            }
        }
        if (ans_idx + 1 > n || query_(ans_idx + 1) != sum) {
            return -1;
        }
        return ans_idx + 1;
    }
};

int main() {
    cin >> n >> m;
    FenwickTree t(n);
    for (int i = 1 ; i <= n ; ++i) {
        int val; cin >> val;
        t.update(i, val);
    }
    while (m--) {
        int type; cin >> type;
        if (type == 0) {
            int a, b; cin >> a >> b;
            t.update(a, b);
        }
        if (type == 1) {
            int a, b; cin >> a >> b;
            cout << t.query(a, b) << "\n";
        }
        if (type == 2) {
            int a; cin >> a;
            cout << t.exact_sum_position(a) << "\n";
        }
    }
    return 0;
}