#include <bits/stdc++.h>
#define LLI long long int
#define FOR(v, a, b) for(LLI v = (a); v < (b); ++v)
#define FORE(v, a, b) for(LLI v = (a); v <= (b); ++v)
#define REP(v, n) FOR(v, 0, n)
#define REPE(v, n) FORE(v, 0, n)
#define REV(v, a, b) for(LLI v = (a); v >= (b); --v)
#define ALL(x) (x).begin(), (x).end()
#define RALL(x) (x).rbegin(), (x).rend()
#define ITR(it, c) for(auto it = (c).begin(); it != (c).end(); ++it)
#define RITR(it, c) for(auto it = (c).rbegin(); it != (c).rend(); ++it)
#define EXIST(c,x) ((c).find(x) != (c).end())
#define fst first
#define snd second
#define popcount __builtin_popcount
#define UNIQ(v) (v).erase(unique(ALL(v)), (v).end())
#define bit(i) (1LL<<(i))

#ifdef DEBUG
#include <misc/C++/Debug.cpp>
#else
#define dump(...) ((void)0)
#endif

#define gcd __gcd

using namespace std;
template <class T> constexpr T lcm(T m, T n){return m/gcd(m,n)*n;}

template <typename I> void join(ostream &ost, I s, I t, string d=" "){for(auto i=s; i!=t; ++i){if(i!=s)ost<<d; ost<<*i;}ost<<endl;}
template <typename T> istream& operator>>(istream &is, vector<T> &v){for(auto &a : v) is >> a; return is;}

template <typename T, typename U> bool chmin(T &a, const U &b){return (a>b ? a=b, true : false);}
template <typename T, typename U> bool chmax(T &a, const U &b){return (a<b ? a=b, true : false);}
template <typename T, size_t N, typename U> void fill_array(T (&a)[N], const U &v){fill((U*)a, (U*)(a+N), v);}

struct Init{
  Init(){
    cin.tie(0);
    ios::sync_with_stdio(false);
  }
}init;

template <typename Monoid> class SegmentTree{
private:
  int size;
  vector<Monoid> vec;
  
  inline Monoid aux(int x, int y, int i, int l, int r){
    if(r<=x || y<=l) return Monoid::identity();
    else if(x<=l && r<=y) return vec[i];
    else return Monoid::op(aux(x,y,i*2+1,l,(l+r)/2), aux(x,y,i*2+2,(l+r)/2,r));
  };

public:
  SegmentTree(int n){
    size = 1;
    while(size < n) size *= 2;
    size = size*2-1;
    vec = vector<Monoid>(size, Monoid::identity());
  }

  inline void update(int i, const Monoid &x){
    int j = i+(size+1)/2-1;
    vec[j] = x;
    --j;
    while(j>=0){
      vec[j/2] = Monoid::op(vec[(j/2)*2+1], vec[(j/2)*2+2]);
      (j /= 2) -= 1;
    }
  }

  inline Monoid at(int i){
  	return vec[(size+1)/2 + i - 1];
  }

  inline Monoid get(int x, int y){ // [x,y)
    return aux(x,y,0,0,(size+1)/2);
  }
};


template <typename T, T NEGINF>
struct MaxPartialSumMonoid{
  T sum, left_max, right_max, partial_max;
  using M = MaxPartialSumMonoid;

  static M op(const M &a, const M &b){
    return MaxPartialSumMonoid({
                                a.sum + b.sum,
                                max({a.left_max, a.sum+b.left_max, a.sum+b.sum}),
                                max({b.right_max, b.sum+a.right_max, a.sum+b.sum}),
                                max({a.partial_max, b.partial_max, a.right_max+b.left_max})
      });
  }
  
  static constexpr M identity(){
    return MaxPartialSumMonoid({0, NEGINF, NEGINF, NEGINF});
  }

  static constexpr M make(const T &a){
    return MaxPartialSumMonoid({a, a, a, a});
  }

  friend ostream& operator<<(ostream &os, const M &val){
    os << val.sum << "," << val.left_max << "," << val.right_max << "," << val.partial_max;
    return os;
  }
};


using M = MaxPartialSumMonoid<LLI,(-(1LL<<50))>;

int main(){
  int N,Q;
  while(cin >> N >> Q){
    SegmentTree<M> seg(N);

    vector<LLI> a(N); cin >> a;
    REP(i,N){
      seg.update(i, M::make(a[i]));
    }

    REP(i,Q){
      string com; cin >> com;

      if(com == "set"){
        int i, x; cin >> i >> x;
        --i;
        seg.update(i, M::make(x));
        a[i] = x;
      }else{
        int l1, l2, r1, r2; cin >> l1 >> l2 >> r1 >> r2;
        --l1, --l2, --r1, --r2;

        r1 = max(l1,r1);
        l2 = min(l2,r2);

        LLI ans = LLONG_MIN;
        
        if(l2 <= r1){
          ans = seg.get(l1,l2+1).right_max + seg.get(l2,r1+1).sum + seg.get(r1,r2+1).left_max - a[r1] - a[l2];
        }else{
          chmax(ans, seg.get(l1,r1+1).right_max + seg.get(r1,r2+1).left_max - a[r1]);
          chmax(ans, seg.get(l1,l2+1).right_max + seg.get(l2,r2+1).left_max - a[l2]);
          chmax(ans, seg.get(r1,l2+1).partial_max);
        }

        cout << ans << endl;
      }
    }

    cerr << endl;
  }


  return 0;
}