import sys

# sys.setrecursionlimit(200005)
int1 = lambda x: int(x)-1
pDB = lambda *x: print(*x, end="\n", file=sys.stderr)
p2D = lambda x: print(*x, sep="\n", end="\n\n", file=sys.stderr)
def II(): return int(sys.stdin.readline())
def LI(): return list(map(int, sys.stdin.readline().split()))
def LLI(rows_number): return [LI() for _ in range(rows_number)]
def LI1(): return list(map(int1, sys.stdin.readline().split()))
def LLI1(rows_number): return [LI1() for _ in range(rows_number)]
def SI(): return sys.stdin.readline().rstrip()
dij = [(0, 1), (-1, 0), (0, -1), (1, 0)]
# dij = [(0, 1), (-1, 0), (0, -1), (1, 0), (1, 1), (1, -1), (-1, 1), (-1, -1)]
inf = (1 << 63)-1
# inf = (1 << 31)-1
# md = 10**9+7
md = 998244353

class LazySegTree:
    def __init__(self, op, e, mapping, composition, _id, v):
        self._op = op
        self._e = e
        self._mapping = mapping
        self._composition = composition
        self._id = _id

        if isinstance(v, int):
            v = [e]*v

        self._n = len(v)
        self._log = (self._n-1).bit_length()
        self._size = 1 << self._log
        self._d = [self._e]*(2*self._size)
        self._lz = [self._id]*self._size
        for i in range(self._n):
            self._d[self._size+i] = v[i]
        for i in range(self._size-1, 0, -1):
            self._update(i)

    def set(self, p, x):
        p += self._size
        for i in range(self._log, 0, -1):
            self._push(p >> i)
        self._d[p] = x
        for i in range(1, self._log+1):
            self._update(p >> i)

    def get(self, p):
        p += self._size
        for i in range(self._log, 0, -1):
            self._push(p >> i)
        return self._d[p]

    def prod(self, left, right):
        if left == right:
            return self._e

        left += self._size
        right += self._size

        for i in range(self._log, 0, -1):
            if ((left >> i) << i) != left:
                self._push(left >> i)
            if ((right >> i) << i) != right:
                self._push(right >> i)

        sml = self._e
        smr = self._e
        while left < right:
            if left & 1:
                sml = self._op(sml, self._d[left])
                left += 1
            if right & 1:
                right -= 1
                smr = self._op(self._d[right], smr)
            left >>= 1
            right >>= 1

        return self._op(sml, smr)

    def all_prod(self):
        return self._d[1]

    def apply(self, left, right, f):
        if right is None:
            p = left
            p += self._size
            for i in range(self._log, 0, -1):
                self._push(p >> i)
            self._d[p] = self._mapping(f, self._d[p])
            for i in range(1, self._log+1):
                self._update(p >> i)
        else:
            if left == right:
                return

            left += self._size
            right += self._size

            for i in range(self._log, 0, -1):
                if ((left >> i) << i) != left:
                    self._push(left >> i)
                if ((right >> i) << i) != right:
                    self._push((right-1) >> i)

            l2 = left
            r2 = right
            while left < right:
                if left & 1:
                    self._all_apply(left, f)
                    left += 1
                if right & 1:
                    right -= 1
                    self._all_apply(right, f)
                left >>= 1
                right >>= 1
            left = l2
            right = r2

            for i in range(1, self._log+1):
                if ((left >> i) << i) != left:
                    self._update(left >> i)
                if ((right >> i) << i) != right:
                    self._update((right-1) >> i)

    def max_right(self, left, g):
        if left == self._n:
            return self._n

        left += self._size
        for i in range(self._log, 0, -1):
            self._push(left >> i)

        sm = self._e
        first = True
        while first or (left & -left) != left:
            first = False
            while left%2 == 0:
                left >>= 1
            if not g(self._op(sm, self._d[left])):
                while left < self._size:
                    self._push(left)
                    left *= 2
                    if g(self._op(sm, self._d[left])):
                        sm = self._op(sm, self._d[left])
                        left += 1
                return left-self._size
            sm = self._op(sm, self._d[left])
            left += 1

        return self._n

    def min_left(self, right, g):
        if right == 0:
            return 0

        right += self._size
        for i in range(self._log, 0, -1):
            self._push((right-1) >> i)

        sm = self._e
        first = True
        while first or (right & -right) != right:
            first = False
            right -= 1
            while right > 1 and right%2:
                right >>= 1
            if not g(self._op(self._d[right], sm)):
                while right < self._size:
                    self._push(right)
                    right = 2*right+1
                    if g(self._op(self._d[right], sm)):
                        sm = self._op(self._d[right], sm)
                        right -= 1
                return right+1-self._size
            sm = self._op(self._d[right], sm)

        return 0

    def _update(self, k):
        self._d[k] = self._op(self._d[2*k], self._d[2*k+1])

    def _all_apply(self, k, f):
        self._d[k] = self._mapping(f, self._d[k])
        if k < self._size:
            self._lz[k] = self._composition(f, self._lz[k])

    def _push(self, k):
        self._all_apply(2*k, self._lz[k])
        self._all_apply(2*k+1, self._lz[k])
        self._lz[k] = self._id

def op(a, b):
    s1, t1, d1 = a
    s2, t2, d2 = b
    return (min(s1, s2), max(t1, t2), max(d1, d2, t2-s1))

e = (inf, -inf, -inf)

def mapping(f, x):
    s, t, d = x
    return (s+f, t+f, d)

def composition(f, g): return f+g

from itertools import accumulate

n, q = LI()
aa = LI()
cs = [0]+list(accumulate(aa))
st = LazySegTree(op, e, mapping, composition, 0, [(s, s, -inf) for s in cs])

for _ in range(q):
    t, *data = SI().split()
    if t == "set":
        i, x = map(int, data)
        i -= 1
        st.apply(i+1, n+1, x-aa[i])
        aa[i] = x
    else:
        l1, l2, r1, r2 = map(int, data)
        l1, l2, r2 = l1-1, l2, r2+1

        s1 = s2 = inf
        t2 = t3 = -inf
        d = -inf
        if l1 < r1:
            s1, _, _ = st.prod(l1, min(l2, r1))

        if l2 < r2:
            _, t3, _ = st.prod(max(l2, r1), r2)

        L = max(l1, r1)
        R = min(l2, r2)
        if R > L:
            s2, t2, d = st.prod(L, R)

        ans = max(d, max(t2, t3)-s1, t3-min(s1, s2))

        print(ans)