#define _USE_MATH_DEFINES
#include "bits/stdc++.h"
using namespace std;
#define FOR(i,j,k) for(int (i)=(j);(i)<(int)(k);++(i))
#define rep(i,j) FOR(i,0,j)
#define each(x,y) for(auto &(x):(y))
#define mp make_pair
#define MT make_tuple
#define all(x) (x).begin(),(x).end()
#define debug(x) cout<<#x<<": "<<(x)<<endl
#define smax(x,y) (x)=max((x),(y))
#define smin(x,y) (x)=min((x),(y))
#define MEM(x,y) memset((x),(y),sizeof (x))
#define sz(x) (int)(x).size()
#define RT return
using ll = long long;
using pii = pair<int, int>;
using vi = vector<int>;
using vll = vector<ll>;

template<class P, class Q>
struct LazySegTree {
    int dataSize;
    vector<P> value;
    vector<Q> lazy;
    function<P(P, P)> f;
    function<P(P, Q)> g;
    function<Q(Q, Q)> h;

    LazySegTree(vector<P> dat,
        function<P(P, P)> f_, function<P(P, Q)> g_, function<Q(Q, Q)> h_){
        f = f_;
        g = g_;
        h = h_;
        dataSize = 1;
        int n = (int)dat.size();
        while (dataSize < n)dataSize *= 2;
        int treeSize = 2 * dataSize;
        value = vector<P>(treeSize, P());
        lazy = vector<Q>(treeSize, Q());
        for (int i = 0; i < n; ++i) {
            value[dataSize + i] = dat[i];
        }
        for (int i = dataSize - 1; i >= 0; --i) {
            value[i] = f(value[i * 2], value[i * 2 + 1]);
        }
    }

    void propagate(int index, int curL, int curR) {
        if (lazy[index] != Q()) {
            int left = index * 2, right = index * 2 + 1;
            value[index] = g(value[index], lazy[index]);
            if (curR - curL > 1) {
                lazy[left] = h(lazy[left], lazy[index]);
                lazy[right] = h(lazy[right], lazy[index]);
            }
            lazy[index] = Q();
        }
    }

    void update(int index, int curL, int curR, int givenL, int givenR, Q x) {
        propagate(index, curL, curR);

        if (curR <= givenL || givenR <= curL)return;

        if (givenL <= curL && curR <= givenR) {
            lazy[index] = h(lazy[index], x);
            propagate(index, curL, curR);
        } else {
            int mid = (curL + curR) / 2;
            update(index * 2, curL, mid, givenL, givenR, x);
            update(index * 2 + 1, mid, curR, givenL, givenR, x);
            value[index] = f(value[index * 2], value[index * 2 + 1]);
        }
    }

    void update(int l, int r, Q x) {
        update(1, 0, dataSize, l, r, x);
    }

    P query(int l, int r) {
        return query(1, 0, dataSize, l, r);
    }

    P query(int index, int curL, int curR, int givenL, int givenR) {
        if (curR <= givenL || givenR <= curL)return P();

        propagate(index, curL, curR);

        if (givenL <= curL && curR <= givenR) {
            return value[index];
        } else {
            int mid = (curL + curR) / 2;
            P resL = query(index * 2, curL, mid, givenL, givenR);
            P resR = query(index * 2 + 1, mid, curR, givenL, givenR);
            return f(resL, resR);
        }
    }
};

struct P {
    ll mi, ma, mm;
    P() {
        mi = LLONG_MAX / 3;
        ma = LLONG_MIN / 3;
        mm = LLONG_MIN / 3;
    }
    P(ll a, ll b, ll c):mi(a),ma(b),mm(c){}
};

P f(P l, P r) {
    return P(min(l.mi, r.mi), max(l.ma, r.ma), max(r.ma - l.mi, max(l.mm, r.mm)));
}

P g(P p, ll q) {
    p.mi += q;
    p.ma += q;
    return p;
}

void solve() {
    int N, Q;
    cin >> N >> Q;
    vll a(N), sm(N + 1);
    rep(i, N) {
        cin >> a[i];
        sm[i + 1] = sm[i] + a[i];
    }
    
    vector<P> ps(N + 1);
    rep(i, N + 1)ps[i] = P(sm[i], sm[i], LLONG_MIN/3);

    LazySegTree<P, ll> lst(ps, f, g, plus<ll>());
    rep(hoge, Q) {
        string s;
        cin >> s;
        if (s == "max") {
            int L1, L2, R1, R2;
            cin >> L1 >> L2 >> R1 >> R2;
            ll ans = LLONG_MIN;
            if (L2 <= R1) {
                ans = lst.query(R1, R2 + 1).ma - lst.query(L1 - 1, L2).mi;
            } else if (L1 <= R1 && R2 <= L2) {
                smax(ans, lst.query(R1, R2 + 1).ma - lst.query(L1 - 1, R1).mi);
                smax(ans, lst.query(R1 - 1, R2 + 1).mm);
            } else if (R1 <= L1 && L2 <= R2) {
                smax(ans, lst.query(L2, R2 + 1).ma - lst.query(L1 - 1, L2).mi);
                smax(ans, lst.query(L1 - 1, L2 + 1).mm);
            } else if (R1 <= L1) {
                ans = lst.query(L1 - 1, R2 + 1).mm;
            }else {
                if (L2 <= R2) {
                    smax(ans, lst.query(L2, R2 + 1).ma - lst.query(L1 - 1, L2).mi);
                }
                if (L1 <= R1) {
                    smax(ans, lst.query(R1, R2 + 1).ma - lst.query(L1 - 1, R1).mi);
                }
                smax(ans, lst.query(R1 - 1, L2 + 1).mm);
            }
            cout << ans << endl;
        } else {
            int i, x;
            cin >> i >> x;
            ll d = x - a[i - 1];
            lst.update(i, N + 1, d);
            a[i - 1] = x;
        }
    }
}

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout << fixed << setprecision(15);
	solve();
	return 0;
}