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

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

int n, op, x, y, m;

vector<long long> t;

void add(int k, int val){
    while(k <= n){
        t[k] += val;
        k += (k & -k);
    }
}

long long sum(int k){
    long long s = 0;
    while(k){
        s += t[k];
        k -= (k & -k);
    }
    
    return s;
}

int main()
{
    int i, left, right, mid, pos;
    long long val;
    
    fin >> n >> m;
    t.resize(n + 1);
    
    for(i = 1; i <= n; ++i){
        fin >> val;
        add(i, val);
    }
    
    
    for(i = 1; i <= m; ++i){
        fin >> op;
        if(op == 0){
            
            fin >> x >> y;
            add(x, y);
            
        }else if(op == 1){
 
            fin >> x >> y;
            fout << sum(y) - sum(x - 1) << endl;
            
        }else{
            
            fin >> x;
            pos = -1;
            left = 1, right = n;
            while(left <= right){
                mid = (left + right) / 2;
                val = sum(mid);
                
                if(val > x){
                    right = mid - 1;
                }else if(val < x){
                    left = mid + 1;
                }else{
                    pos = mid;
                    break;
                }
            }
            fout << pos << endl;
            
        }
    }

    return 0;
}