#include <bits/stdc++.h>
#define show(x) std::cerr << #x << " = " << (x) << std::endl
using ll = long long;
using ull = unsigned long long;
template <typename T>
constexpr T INF = std::numeric_limits<T>::max() / 10;
std::mt19937 mt{std::random_device{}()};
constexpr std::size_t PC(ull v) { return v = (v & 0x5555555555555555ULL) + (v >> 1 & 0x5555555555555555ULL), v = (v & 0x3333333333333333ULL) + (v >> 2 & 0x3333333333333333ULL), v = (v + (v >> 4)) & 0x0F0F0F0F0F0F0F0FULL, static_cast<std::size_t>(v * 0x0101010101010101ULL >> 56 & 0x7f); }
constexpr std::size_t LG(ull v) { return v == 0 ? 0 : (v--, v |= (v >> 1), v |= (v >> 2), v |= (v >> 4), v |= (v >> 8), v |= (v >> 16), v |= (v >> 32), PC(v)); }
constexpr ull SZ(const ull v) { return 1ULL << LG(v); }
template <typename Monoid>
class SegmentTree
{
public:
    using BaseMonoid = Monoid;
    using T = typename Monoid::T;
    SegmentTree(const std::size_t n) : data_num(n), half(SZ(n)), value(half << 1, Monoid::id()) {}
    template <typename InIt>
    SegmentTree(const InIt first, const InIt last) : data_num(distance(first, last)), half(SZ(data_num)), value(half << 1, Monoid::id())
    {
        std::copy(first, last, value.begin() + half);
        for (std::size_t i = half - 1; i >= 1; i--) { up(i); }
    }
    void set(std::size_t a, const T& val)
    {
        value[a += half] = val;
        while (a >>= 1) { up(a); }
    }
    T accumulate(std::size_t L, std::size_t R) const
    {
        T accl = Monoid::id(), accr = Monoid::id();
        for (L += half, R += half; L < R; L >>= 1, R >>= 1) {
            if (L & 1) { accl = acc(accl, value[L++]); }
            if (R & 1) { accr = acc(value[--R], accr); }
        }
        return acc(accl, accr);
    }

private:
    void up(const std::size_t i) { value[i] = acc(value[i << 1], value[i << 1 | 1]); }
    const std::size_t data_num, half;
    std::vector<T> value;
    const Monoid acc{};
};
struct PreSuf
{
    struct T
    {
        ll prefix, suffix, sum, sub;
    };
    T operator()(const T& a, const T& b) const
    {
        return T{
            std::max(a.prefix, a.sum + b.prefix),
            std::max(b.suffix, a.suffix + b.sum),
            a.sum + b.sum,
            std::max({a.prefix, a.sum + b.prefix, b.suffix, a.suffix + b.sum, a.sub, b.sub, a.suffix + b.prefix}),
        };
    }
    static T id() { return T{-INF<ll>, -INF<ll>, 0, -INF<ll>}; }
};
int main()
{
    std::cin.tie(0);
    std::ios::sync_with_stdio(false);
    int N, Q;
    std::cin >> N >> Q;
    std::vector<PreSuf::T> v(N + 1, PreSuf::id());
    for (int i = 1, a; i <= N; i++) { std::cin >> a, v[i] = {a, a, a, a}; }
    SegmentTree<PreSuf> seg(v.begin(), v.end());
    for (int q = 0; q < Q; q++) {
        std::string s;
        std::cin >> s;
        if (s == "set") {
            int i, x;
            std::cin >> i >> x;
            seg.set(i, PreSuf::T{x, x, x, x});
        } else {
            int l1, l2, r1, r2;
            std::cin >> l1 >> l2 >> r1 >> r2, r1 = std::max(l1, r1), l2 = std::min(l2, r2);
            if (l2 < r1) {
                const auto L = seg.accumulate(l1, l2 + 1);
                const auto R = seg.accumulate(r1, r2 + 1);
                const auto M = seg.accumulate(l2 + 1, r1);
                std::cout << L.suffix + M.sum + R.prefix << "\n";
            } else {
                const auto L1 = seg.accumulate(l1, r1);
                const auto R1 = seg.accumulate(r1, r2 + 1);
                const auto L2 = seg.accumulate(l1, l2 + 1);
                const auto R2 = seg.accumulate(l2 + 1, r2 + 1);
                const auto M = seg.accumulate(r1, l2 + 1);
                std::cout << std::max({L1.suffix + R1.prefix, L2.suffix + R2.prefix, M.sub}) << "\n";
            }
        }
    }
    return 0;
}