segtree

#include<bits/stdc++.h>
#define nl "\n"
#define fi first
#define se second
#define pi 3.14159
#define ll long long
#define odd(a)  (a&1)
#define even(a)  !(a&1)
#define Mod 1'000'000'007
#define INF 2'000'000'000
#define sz(x) int(x.size())
#define charToInt(s) (s - '0')
#define ull unsigned long long
#define number_line iota(all(vec) , 1)
#define all(s) s.begin(), s.end()
#define rall(v) v.rbegin() , v.rend()
#define fixed(n) fixed << setprecision(n)
#define Num_of_Digits(n) ((int)log10(n) + 1)
#define to_decimal(bin) stoll(bin, nullptr, 2)
#define Ceil(n, m) (((n) / (m)) + ((n) % (m) ? 1 : 0))
#define Floor(n, m) (((n) / (m)) - ((n) % (m) ? 0 : 1))
#define Upper(s) transform(all(s), s.begin(), ::toupper);
#define Lower(s) transform(all(s), s.begin(), ::tolower);
#define cout_map(mp) for(auto& [f, s] : mp) cout << f << "  " << s << "\n";
//  ----- bits-------
#define pcnt(n) __builtin_popcount(n)
#define pcntll(n) __builtin_popcountll(n)
#define clz(n) __builtin_clz(n)    // <---100
#define clzll(n) __builtin_clzll(n)
#define ctz(n) __builtin_ctz(n)  // 0001---->
#define ctzll(n) __builtin_ctzll(n)

using namespace std;

template < typename T = int > istream& operator >> (istream &in, vector < T > & v){
    for(auto & x : v) in >> x;
    return in;
}

template < typename T = int > ostream& operator << (ostream &out, const vector < T > & v){
    for(const T & x : v) out << x << nl;
    return out;
}

void esraa()
{
   // freopen("input.txt", "r", stdin), freopen("output.txt", "w", stdout);
    ios_base::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
#ifndef ONLINE_JUDGE
    freopen("input.txt", "r", stdin), freopen("output.txt", "w", stdout);
#endif
}
struct segtree{
    int size;
    vector < ll > sums;

    void init(int n){
        size = 1;
        while(size < n) size *= 2;
        sums.assign(2 * size, 0LL);
    }
    void build(vector < ll > &a, int x, int lx, int rx){
        if(rx - lx == 1){
            if(lx < sz(a)){
                sums[x] = a[lx];
            }
            return;
        }
        int m = (lx + rx) / 2;
        build(a, 2 * x + 1, lx, m);
        build(a, 2 * x + 2, m, rx);
        sums[x] = sums[2 * x + 1] + sums[2 * x + 2];
    }

    void build(vector < ll > &a){
        build(a, 0, 0, size);
    }

    void set(int i, int v, int x, int lx, int rx){
        if(rx - lx == 1){
            sums[x] = v;
            return;
        }
        int m = (lx + rx) / 2;
        if(i < m){
            set(i, v, 2 * x + 1, lx, m);
        }else{
            set(i, v, 2 * x + 2, m, rx);
        }
        sums[x] = sums[2 * x + 1] + sums[2 * x + 2];
    }

    void set(int i, int v){
        set(i, v, 0, 0, size);
    }

    ll sum(int l, int r, int x, int lx, int rx){
        if(lx >= r or l >= rx) return 0;
        if(lx >= l and rx <= r) return sums[x];
        int m = (lx + rx) / 2;
        ll s1 = sum(l, r, 2 * x + 1, lx, m);
        ll s2 = sum(l, r, 2 * x + 2, m, rx);
        return s1 + s2;
    }

    ll sum(int l, int r){
        return sum(l, r, 0, 0, size);
    }
};
void solve(){
    int n, m;
    cin >> n >> m;
    segtree st;
    st.init(n);
    vector < ll > a(n);
    cin >> a;
    st.build(a);
    while(m--){
        int op;
        cin >> op;
        if(op == 1){
            int i, v;
            cin >> i >> v;
            st.set(i, v);
        }else{
            int l, r;
            cin >> l >> r;
            cout << st.sum(l, r) << nl;
        }
    }

}
int main()
{
    esraa();
    int t = 1;
   // cin >> t;
    //cin.ignore();
    while(t--)
      solve();
    return 0;
}