template<class T>
struct Fen {
    int n;
    vector<T> t;
    Fen (int n_) {
        init(n_);
    }
    Fen () {};
    void init(int n_) {
        n = n_;
        t.assign(n + 1, {});
    }
    void change(int u, T x) {
        for(; u <= n; u += u & -u) t[u] += x;
    }
    T sum(int u) {
        T res = 0;
        for(; u; u -= u & -u) res += t[u];
        return res;
    }
    T sum(int l, int r) {
        return sum(r) - sum(l - 1);
    }

    int kth(T sum) {
        int i = 0;
        T tot = {};
        for (int j = 1 << __lg(n); j > 0; j /= 2) {
            if (i + j <= n && t[i + j] + tot < sum) {
                i += j;
                tot += t[i];
            }
        }
        return i + 1;
    }
};
void solve() {
    int n, m;
    cin >> n >> m;

    Fen<ll> t1(n + 1), t2(n + 1);
    auto add = [&] (int i, int x) {
        t1.change(i, x);
        t2.change(i, 1ll * x * (n + 1 - i));
    };
    auto query = [&] (int i) {
        return t2.sum(i) - (n - i) * t1.sum(i);
    };

    vector<int> a(n + 1);
    for (int i = 1; i <= n; i++) {
        int x; cin >> x; add(i, x); a[i] = x;
    }

    while (m--) {
        string o; int x, y;
        cin >> o >> x;
        if (o[0] == 'Q') {
            cout << query(x) << '\n';
        } else {
            cin >> y;
            add(x, y - a[x]);
            a[x] = y;
        }
    }
}