#include <bits/stdc++.h>
using namespace std;
using uint = unsigned int;
using ll = long long;
using ull = unsigned long long;
using pii = pair<int, int>;
using pll = pair<long long, long long>;
template <class T> using vec = vector<T>;
template <class T> using vvec = vector<vector<T>>;
#define rep(i, n) for (int i = 0; i < (n); i++)
#define rrep(i, n) for (int i = int(n) - 1; i >= 0; i--)
#define all(x) begin(x), end(x)
constexpr char ln = '\n';
template <class Container> inline int SZ(const Container& v) { return int(v.size()); }
template <class T> inline void UNIQUE(vector<T>& v) { v.erase(unique(v.begin(), v.end()), v.end()); }
template <class T1, class T2> inline bool chmax(T1& a, T2 b) { if (a < b) { a = b; return true; } return false; }
template <class T1, class T2> inline bool chmin(T1& a, T2 b) { if (a > b) { a = b; return true; } return false; }
inline int topbit(ull x) { return x == 0 ? -1 : 63 - __builtin_clzll(x); }
inline int botbit(ull x) { return x == 0 ? 64 : __builtin_ctzll(x); }
inline int popcount(ull x) { return __builtin_popcountll(x); }
inline int kthbit(ull x, int k) { return (x >> k) & 1; }
inline constexpr long long TEN(int x) { return x == 0 ? 1 : TEN(x - 1) * 10; }
const string YESNO[2] = {"NO", "YES"};
const string YesNo[2] = {"No", "Yes"};
inline void YES(bool t = true) { cout << YESNO[t] << "\n"; }
inline void Yes(bool t = true) { cout << YesNo[t] << "\n"; }
template <class T> inline void drop(T x) { cout << x << "\n"; exit(0); }
inline void print() { cout << "\n"; }
template <class T> inline void print(const vector<T>& v) { for (auto it = v.begin(); it != v.end(); ++it) { if (it != v.begin()) { cout << " "; } cout << *it; } print(); }
template <class T, class... Args> inline void print(const T& x, const Args& ... args) { cout << x << " "; print(args...); }
#ifdef MINATO_LOCAL
template <class T1, class T2> ostream& operator<<(ostream& os, pair<T1, T2> p) { return os << "(" << p.first << ", " << p.second << ")"; }
template <size_t N, class TUPLE> void debug_tuple(ostream& os, TUPLE _) { (void)os; (void)_; }
template <size_t N, class TUPLE, class T, class ...Args> void debug_tuple(ostream &os, TUPLE t) { os << (N == 0 ? "" : ", ") << get<N>(t); debug_tuple<N + 1, TUPLE, Args...>(os, t); }
template <class ...Args> ostream& operator<<(ostream& os, tuple<Args...> t) { os << "("; debug_tuple<0, tuple<Args...>, Args...>(os, t); return os << ")"; }
string debug_delim(int& i) { return i++ == 0 ? "" : ", "; }
#define debug_embrace(x) { int i = 0; os << "{";  { x } return os << "}"; }
template <class T> ostream& operator<<(ostream& os, vector<T> v) { debug_embrace( for (T e : v) { os << debug_delim(i) << e; } ) }
template <class T, size_t N> ostream& operator<<(ostream& os, array<T, N> a) { debug_embrace( for (T e : a) { os << debug_delim(i) << e; } ) }
template <class T, size_t N> enable_if_t<!is_same_v<char, remove_cv_t<T>>, ostream>& operator<<(ostream& os, T(&a)[N]) { debug_embrace( for (T e : a) { os << debug_delim(i) << e; } ) }
template <class Key> ostream& operator<<(ostream& os, set<Key> s) { debug_embrace( for (Key e : s) { os << debug_delim(i) << e; }) }
template <class Key, class T> ostream& operator<<(ostream& os, map<Key, T> mp) { debug_embrace( for (auto e : mp) { os << debug_delim(i) << e; }) }
template <class Key> ostream& operator<<(ostream& os, multiset<Key> s) { debug_embrace( for (Key e : s) { os << debug_delim(i) << e; }) }
template <class T> ostream& operator<<(ostream& os, queue<T> q) { debug_embrace( for (; !q.empty(); q.pop()) { os << debug_delim(i) << q.front(); } ) }
template <class T> ostream& operator<<(ostream& os, deque<T> q) { debug_embrace( for (T e : q) { os << debug_delim(i) << e; } ) }
template <class T> ostream& operator<<(ostream& os, priority_queue<T> q) { debug_embrace( for (; !q.empty(); q.pop()) { os << debug_delim(i) << q.top(); } ) }
template <class T> ostream& operator<<(ostream& os, priority_queue<T, vector<T>, greater<T>> q) { debug_embrace( for (; !q.empty(); q.pop()) { os << debug_delim(i) << q.top(); } ) }
void debug_out() { cerr << endl; }
template <class T, class... Args> void debug_out(const T& x, const Args& ... args) { cerr << " " << x; debug_out(args...); }
#define debug(...) cerr << __LINE__ << " : [" << #__VA_ARGS__ << "] =", debug_out(__VA_ARGS__)
#else
#define debug(...) (void(0))
#endif
struct fast_ios { fast_ios() { cin.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(20); cerr << fixed << setprecision(7); }; } fast_ios_;
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

template<class T, class F>
struct SegmentTree {
  private:
    F op;
    T e;
    int _n, size ,log;
    vector<T> node;

  public:
    SegmentTree() {}
    SegmentTree(const F& op, T e, int n) : SegmentTree(op, e, vector<T>(n, e)) {}
    SegmentTree(const F& op, T e, const vector<T>& v) : op(op), e(e), _n(int(v.size())), log(0) {
        while ((1<<log) < _n) log++;
        size = 1 << log;
        node = vector<T> (2 * size, e);
        for (int i = 0; i < _n; i++) node[size + i] = v[i];
        for (int i = size - 1; i >= 1; i--) {
            update(i);
        }
    }

    // (0-indexed)
    void set(int p, T x) {
        assert(0 <= p && p < _n);
        p += size;
        node[p] = x;
        for (int i = 1; i <= log; i++) update(p >> i);
    }

    // [l, r) (0-indexed)
    T get(int l, int r) {
        if (l >= r) return e;
        T resl = e, resr = e;
        l += size; r += size;
        while (l < r) {
            if (l & 1) resl = op(resl, node[l++]);
            l >>= 1;
            if (r & 1) resr = op(node[--r], resr);
            r >>= 1;
        }
        return op(resl, resr);
    }

    T all_get() { return node[1]; }

    template<class C> 
    int max_right(int l, const C& check) {
        assert(0 <= l && l <= _n);
        assert(check(e));
        if (l == _n) return _n;
        l += size;
        T sm = e;
        do {
            while (~l & 1) l >>= 1;
            if (!check(op(sm, node[l]))) {
                while (l < size) {
                    l = (2 * l);
                    if (check(op(sm, node[l]))) {
                        sm = op(sm, node[l]);
                        l++;
                    }
                }
                return l - size;
            }
            sm = op(sm, node[l]);
            l++;
        } while ((l & -l) != l);
        return _n;
    }

    template<class C> 
    int min_left(int r, const C& check) {
        assert(0 <= r && r <= _n);
        assert(check(e));
        if (r == 0) return 0;
        r += size;
        T sm = e;
        do {
            r--;
            while (r > 1 && (r & 1)) r >>= 1;
            if (!check(op(node[r], sm))) {
                while (r < size) {
                    r = (2 * r + 1);
                    if (check(op(node[r], sm))) {
                        sm = op(node[r], sm);
                        r--;
                    }
                }
                return r + 1 - size;
            }
            sm = op(node[r], sm);
        } while ((r & -r) != r);
        return 0;
    }

    T operator[](int p) {
        assert(0 <= p && p < _n);
        return node[p + size];
    }

  private:

    void update(int k) { node[k] = op(node[2 * k], node[2 * k + 1]); }
};

struct Node {
    ll sum_max, sum_all, left_sum_max, right_sum_max;
};

const ll INF = 1e18;
int main() {
    int N,Q; cin >> N >> Q;
    vec<ll> A(N);
    rep(i,N) cin >> A[i];

    auto f=[](Node a, Node b) {
        ll sum_max = max({a.sum_max, b.sum_max, a.right_sum_max + b.left_sum_max});
        ll sum_all = a.sum_all + b.sum_all;
        ll left_sum_max = max(a.left_sum_max, a.sum_all + b.left_sum_max);
        ll right_sum_max = max(b.right_sum_max, b.sum_all + a.right_sum_max);
        return Node{sum_max,sum_all,left_sum_max,right_sum_max};
    };
    const Node e = Node{-INF,0,-INF,-INF};
    vec<Node> arr(N);
    rep(i,N) {
        arr[i] = Node{A[i],A[i],A[i],A[i]};
    }
    SegmentTree seg(f,e,arr);

    rep(_,Q) {
        string s; cin >> s;
        if (s == "set") {
            int p,x; cin >> p >> x;
            p--;
            seg.set(p,Node{x,x,x,x});
            A[p] = x;
        } else {
            int l1,l2,r1,r2; cin >> l1 >> l2 >> r1 >> r2;
            l1--; l2--; r1--; r2--;
            chmin(l2,r2);
            chmax(r1,l1);
            if (l2 < r1) {
                ll ans = l2 + 1 == r1 ? 0 : seg.get(l2+1,r1).sum_all;
                ans += seg.get(l1,l2+1).right_sum_max + seg.get(r1,r2+1).left_sum_max;
                cout << ans << ln;
            } else {
                if (l2==r1) {
                    ll ans = seg[l2].sum_all;
                    ans += max(0LL, seg.get(l1,l2).right_sum_max);
                    ans += max(0LL, seg.get(r1+1,r2+1).left_sum_max);
                    cout << ans << ln;
                } else {
                    ll vall = A[r1] + max(0LL, seg.get(l1,r1).right_sum_max);
                    ll valr = A[l2] + max(0LL, seg.get(l2+1,r2+1).left_sum_max);
                    seg.set(r1,Node{vall,vall,vall,vall});
                    seg.set(l2,Node{valr,valr,valr,valr});
                    cout << seg.get(r1,l2+1).sum_max << ln;
                    seg.set(r1,Node{A[r1],A[r1],A[r1],A[r1]});
                    seg.set(l2,Node{A[l2],A[l2],A[l2],A[l2]});
                }
            }
        }
    }
}