/*
    Programmer : Alexandru Olteanu
*/
#include<bits/stdc++.h>
using namespace std;
// GCC Optimizations
// #pragma GCC optimize("Ofast");
// #pragma GCC target("fma,sse,sse2,sse3,ssse3,sse4,popcnt")
// #pragma GCC target("abm,mmx,avx,avx2,tune=native")
// #pragma GCC optimize(3)
// #pragma GCC optimize("inline")
// #pragma GCC optimize("-fgcse")
// #pragma GCC optimize("-fgcse-lm")
// #pragma GCC optimize("-fipa-sra")
// #pragma GCC optimize("-ftree-pre")
// #pragma GCC optimize("-ftree-vrp")
// #pragma GCC optimize("-fpeephole2")
// #pragma GCC optimize("-ffast-math")
// #pragma GCC optimize("-fsched-spec")
// #pragma GCC optimize("unroll-loops")
// Useful
mt19937 rng((unsigned int) chrono::steady_clock::now().time_since_epoch().count());
#define FastEverything  ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define HighPrecision cout<<fixed<<setprecision(17);
typedef long long ll;
typedef pair<int,int> pii;
ll const mod=1000000007LL;
ll const mod2 = 100000000LL;
ll const md=998244353LL;
ll mypowr(ll a,ll b, ll mod1) {ll res=1;if(b<0)b=0;a%=mod1; assert(b>=0);
for(;b;b>>=1){if(b&1)res=res*a%mod1;a=a*a%mod1;}return res;}
ll mypow(ll a,ll b) {ll res=1;if(b<0)b=0;assert(b>=0);
for(;b;b>>=1){if(b&1)res=res*a;a=a*a;}return res;}
#define pb push_back
#define fi first
#define se second
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(), x.rend()

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

const ll infll = 9e18;
const int inf = 2e9;
const ll maxn = 2e5 + 2;

/*
    Template created by Alexandru Olteanu
*/
template<typename A>
struct FenwickTree{
    vector<A> array;
    int n;
    FenwickTree(int length){
        array.resize(length + 1);
        n = length;
    }

    void modify(int x, ll val){
        for(; x <= n; x += x & -x){
            array[x] += val;
        }
        return;
    }
    
    ll calc(int x){
        ll val = 0;
        for(; x > 0; x -= x & -x){
            val += array[x];
        }
        return val;
    }
    
    ll get(int l, int r){
        return calc(r) - calc(l - 1);   
    }
};

int main()
{
    FastEverything
    HighPrecision

    int test = 1;
    // cin >> test;
    for (int tt = 1; tt <= test; ++tt) {
        int n, m;
        cin >> n >> m;
        FenwickTree<int> f(n);
        for (int i = 1; i <= n; ++i) {
            int x;
            cin >> x;
            f.modify(i, x);
        }
        for (int i = 1; i <= m; ++i) {
            int p, x, y;
            cin >> p >> x;
            if (p == 0) {
                cin >> y;
                f.modify(x, y);
            }
            if (p == 1) {
                cin >> y;
                cout << f.get(x, y) << '\n';
            }
            if (p == 2) {
                int left = 1, right = n;
                int answer = -1;
                while (left <= right) {
                    int mid = left + (right - left) / 2;
                    int res = f.get(1, mid);
                    if (res == x) {
                        answer = mid;
                        right = mid - 1;
                        continue;
                    }
                    if (res < x) {
                        left = mid + 1;
                    }
                    else {
                        right = mid - 1;
                    }
                }
                cout << answer << '\n';
            }
        }
    }

    return 0;
}