#include <bits/stdc++.h>
#define ll long long
#define cin fin
#define cout fout
using namespace std;
ifstream fin("aib.in");
ofstream fout("aib.out");
int n, m, a, b, val;
int BIT[400099];

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

int prefixSum(int index) {
    int result = 0;

    while (index) {
        result += BIT[index];
        index -= index & (-index);
    }

    return result;
}

int sumOfInterval(int a, int b) {
    return prefixSum(b) - prefixSum(a - 1);
}

int main() {
    ios :: sync_with_stdio(0);
    cin.tie(0);

    cin >> n >> m;
    for (int i = 1; i <= n; i++) {
        cin >> val;
        update(i, val);
    }

    int type;
    for (int query = 1; query <= m; query++) {
        cin >> type;

        if (!type) {
            cin >> a >> b;
            update(a, b);
        } else if (type == 1) {
            cin >> a >> b;
            cout << sumOfInterval(a, b) << '\n';
        } else {
            cin >> val;

            //binary searching for the answer
            int left = 1, right = n;
            while (left < right) {
                int mid = (right + left) / 2;

                if (prefixSum(mid) >= val)
                    right = mid;
                else
                    left = mid + 1;
            }

            if (prefixSum(left) == val)
                cout << left << '\n';
            else
                cout << "-1\n";
        }
    }

    return 0;
}