#include<cstdio>

#include<cstring>

#include<algorithm>

#define for1(i,a,b) for(int i=(a);i<=(b);++i)

using namespace std;

typedef long long ll;

const int N=1E5+;

int n,m,data[N];

struct node{

    node();

    node *ch[],*fa;

    ll d,sum,set,add[]; int size; short vset;

    short pl() {return this==fa->ch[];}

    void count(); void push();

    void mark(ll,ll,short);

}*null;

node::node(){ch[]=ch[]=fa=null; size=vset=sum=add[]=add[]=;}

void node::mark(ll val,ll dd,short t){

    if(this==null) return;

    if(!t){

        set=val;

        sum=size*set;

        d=set;

        vset=;

        add[]=add[]=;

    }else{

        add[]+=val;

        add[]+=dd;

        sum+=val*size;

        sum+=dd*size*(size-)/;

        d+=val+dd*(ch[]->size);

    }

}

void node::push(){

    if(this==null)return;

    if(vset){

        ch[]->mark(set,,);

        ch[]->mark(set,,);

        vset=; set=;

    }

    if(add[]||add[]){

        ch[]->mark(add[],add[],);

        ch[]->mark(add[]+add[]*(ch[]->size+),add[],);

        add[]=add[]=;

    }

}

void node::count(){

    size=ch[]->size+ch[]->size+;

    sum=ch[]->sum+ch[]->sum+d;

}

namespace Splay{

    node *ROOT;

    node *build(int l=,int r=n){

        if (l>r) return null;

        int mid=(l+r)>>;

        node *ro=new node;

        ro->d=data[mid];

        ro->ch[]=build(l,mid-);

        ro->ch[]=build(mid+,r);

        ro->ch[]->fa=ro;

        ro->ch[]->fa=ro;

        ro->count();

        return ro;

    }

    void Build(){

        null=new node;

        *null=node();

        ROOT=build();

    }

    void rotate(node *k){

        node *r=k->fa; if (k==null||r==null) return;

        r->push(); k->push();

        int x=k->pl()^;;

        r->ch[x^]=k->ch[x];

        r->ch[x^]->fa=r;

        if (r->fa!=null) r->fa->ch[r->pl()]=k;

        else ROOT=k;

        k->fa=r->fa; r->fa=k;

        k->ch[x]=r;

        r->count(); k->count();

    }

    void splay(node *r,node *tar=null){

        for (;r->fa!=tar;rotate(r))

         if (r->fa->fa!=tar)rotate(r->pl()==r->fa->pl()?r->fa:r);

        r->push();

    }

    void insert(int x,int val){

        node *r=ROOT;

        if (ROOT==null){

            ROOT=new node;

            ROOT->d=val;

            ROOT->count();

            return;

        }

        while ()

        {

            r->push();

            int c;

            if (r->ch[]->size+>=x) c=;

            else c=,x-=r->ch[]->size+;

            if (r->ch[c]==null){

                r->ch[c]=new node;

                r->ch[c]->fa=r;

                r->ch[c]->d=val;

                splay(r->ch[c]);

                return;

            }else r=r->ch[c];

        }

    }

    node *kth(int k){

        node *r=ROOT;

        while (r!=null){

            r->push();

            if (r->ch[]->size>=k) r=r->ch[];

            else if (r->ch[]->size+>=k) return r;

            else k-=r->ch[]->size+,r=r->ch[];

        }

        return null;

    }

    node *pack(int l,int r){

        node *ln=kth(l-),*rn=kth(r+);

        if ((ln==null)&&(rn==null)) return ROOT;

        else if (ln==null){

            splay(rn); return rn->ch[];

        }else if (rn==null){

            splay(ln); return ln->ch[];

        }else{

            splay(ln); splay(rn,ROOT);

            return rn->ch[];

        }

    }

}

int main(){

    scanf("%d%d",&n,&m);

    for1(i,,n)scanf("%d",&data[i]);

    Splay::Build(); int j,a,b,c;

    for1(i,,m){

        scanf("%d",&j);

        switch(j){

            node *r;

            case :

                scanf("%d%d%d",&a,&b,&c);

                r=Splay::pack(a,b);

                r->mark(c,,);

                Splay::splay(r);

            break;

            case :

                scanf("%d%d%d",&a,&b,&c);

                r=Splay::pack(a,b);

                r->mark(c,c,);

                Splay::splay(r);

            break;

            case :

                scanf("%d%d",&a,&b);

                Splay::insert(a,b);

            break;

            case :

                scanf("%d%d",&a,&b);

                r=Splay::pack(a,b);

                printf("%lld\n",r->sum);

            break;

        }

    }

    return  ;

}