#include <iostream>
#include <fstream>
#define MAX 100002
using namespace std;
int n,m,aib[MAX],x,t,a,b;

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

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

int query(int pos){
    int ans = 0;
    for(int i = pos; i > 0; i -= (i&-i)){
        ans += aib[i];
    }
    return ans;
}

int query(int st, int dr){
    return query(dr)-query(st-1);
}

int main()
{
    fin >> n >> m;
    for(int i = 1; i <= n; i++){
        fin >> x;
        update(i, x);
    }
    while(m--){
        fin >> t >> a;
        if(t == 0){
            fin >> b;
            update(a, b);
        }else if(t == 1){
            fin >> b;
            fout << query(a, b) << "\n";
        }else if(t == 2){
            int st = 1, dr = n;
            int ans = -1;
            while(st <= dr){
                int mid = (st+dr)/2;
                int val = query(mid);
                if(val == a){
                    ans = mid;
                    break;
                }
                if(val > a){
                    dr = mid-1;
                }else{
                    st = mid+1;
                }
            }
            fout << ans << "\n";
        }
    }
    return 0;
}