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

#ifdef LOCAL
#include "debug.h"
#else
#define debug(x...)
#endif

using ll = long long;
using ull = unsigned long long;
using db = long double;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using pdd = pair<db, db>;
using tiii = tuple<int, int, int>;
using str = string;

#define vt vector
#define pb push_back
#define eb emplace_back
#define ins insert
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define sz(x) (int)x.size()

#define mp make_pair
#define mt make_tuple
#define fi first
#define se second

struct segtree {

    struct node {
        int ch, nch;
    };


    vt<node> tree;
    int size;

    node zero = {0, 0};


    void init(int n) {
        size = 1;
        while (size < n) size *= 2;
        tree.assign(2 * size - 1, zero);
    }
    

    void build(vt<int> &a, int x, int lx, int rx) {
        if (rx == lx + 1) {
            if (lx < size) {
                if (lx % 2 == 0) {
                    tree[x].ch = a[lx];
                    // tree[x].nch = 0;
                } else {
                    // tree[x].ch = 0;
                    tree[x].nch = a[lx];
                }
                // сout << lx << ' ' << rx << endl;
            }
        } else {
            int m = (lx + rx) / 2;
            build(a, 2 * x + 1, lx, m);
            build(a, 2 * x + 2, m, rx);
            tree[x].ch = tree[2 * x + 1].ch + tree[2 * x + 2].ch;
            tree[x].nch = tree[2 * x + 1].nch + tree[2 * x + 2].nch;

        }
    }

    void build(vt<int> &a) {
        init(sz(a));
        build(a, 0, 0, size);
    }

    void update(int i, int v, int x, int lx, int rx) {
        if (rx == lx + 1) {
            if (i % 2 == 0) {
                tree[x].ch = v;
            } else {
                tree[x].nch = v;
            }
            return;
        }
        int m = (lx + rx) / 2;
        if (i < m) {
            update(i, v, 2 * x + 1, lx, m);
        } else {
            update(i, v, 2 * x + 2, m, rx);
        }
        tree[x].ch = tree[2 * x + 1].ch + tree[2 * x + 2].ch;
        tree[x].nch = tree[2 * x + 1].nch + tree[2 * x + 2].nch;
    }


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

    ll sumch(int l, int r, int x, int lx, int rx) {
        if (r <= lx || l >= rx) {
            return 0;
        }
        if (lx >= l && rx <= r) {
            return tree[x].ch;
        }
        int m = (lx + rx) / 2;
        int ans = sumch(l, r, 2 * x + 1, lx, m);
        int ans1  = sumch(l, r, 2 * x + 2, m, rx);
        return ans + ans1;
    }



    ll sumch(int l, int r) {
        return sumch(l, r, 0, 0, size);
    }



    ll sumnch(int l, int r, int x, int lx, int rx) {
        if (r <= lx || l >= rx) {
            return 0;
        }
        if (lx >= l && rx <= r) {
            return tree[x].nch;
        }
        int m = (lx + rx) / 2;
        int ans = sumnch(l, r, 2 * x + 1, lx, m);
        int ans1  = sumnch(l, r, 2 * x + 2, m, rx);
        return ans + ans1;
    }



    ll sumnch(int l, int r) {
        return sumnch(l, r, 0, 0, size);
    }



};

void solve() {
    int n;
    cin >> n;
    vt<int> a(n);
    for (int i = 0; i < n; ++i) {
        cin >> a[i];
    }

    segtree st;
    st.build(a);

    // for (auto i : st.tree) {
    //     cout << "{" << i.ch << ", " << i.nch << "}" << ' ';
    // }
    // cout << endl;

    int m;
    cin >> m;
    while (m--) {
        int f;
        cin >> f;
        if (f == 0) {
            int i, j;
            cin >> i >> j;
            i--;
            st.update(i, j);
            // for (auto e : st.tree) { 
            //     cout << "{" << e.ch << ", " << e.nch << "}" << ' ';
            // }
            // cout << endl;
        } else {
            int l, r;
            cin >> l >> r;
            l--;
            int a1 = st.sumch(l, r);
            int a2 = st.sumnch(l, r);
            // cout << a1 << ' ' << a2 << endl;
            if (l % 2 == 0) cout << a1 - a2 << endl;
            else cout << a2 - a1 << endl;
        }
    }
}

signed main() {
    ios::sync_with_stdio(false);
    cin.tie(NULL);
    // freopen("input.txt", "r", stdin);
    // freopen("output.txt", "w", stdout);
    int tests = 1;
    // cin >> tests;
    while (tests--) {
        solve();
    }
    return 0;
}