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

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

int n, m, aib[100005];

void update(int p, int x) {
    for( ; p <= n; p += (p&(-p)))
        aib[p] += x;
}

int query(int p) {
    int sum = 0;
    for(; p > 0; p -= (p&(-p)))
        sum += aib[p];
    return sum;
}

int bs(int x) {
    int l = 0, r = n, ans = -1;
    while(l <= r) {
        int m = l+(r-l)/2;
        int q = query(m);
        if(q >= x) {
            if(q == x) ans = m;
            r = m-1;
        } else {
            l = m+1;
        }
    }
    return ans;
}

int main() {
    fin >> n >> m;
    for(int i = 1; i <= n; i++) {
        int x;
        fin >> x;
        update(i, x);
    }
    while(m--) {
        int t, a, b;
        fin >> t;
        if(t == 2) fin >> a;
        else fin >> a >> b;

        if(t == 0) update(a, b);
        else if(t == 1) fout << query(b)-query(a-1) << '\n';
        else fout << bs(a) << '\n';
    }
}