why 60pts

#include<bits/stdc++.h>
#define int long long
using namespace std;
namespace Tree{
    const int maxn=1000005;
    int n,q;
    int val[maxn];
    struct tree{
        int l,r;
        int lson,rson;
        int maxx;
        int cov,add;
    }a[maxn*4];
    void pushup(int x){
        a[x].maxx=max(a[a[x].lson].maxx,a[a[x].rson].maxx);
    }
    int cnt=0;
    int Root;
    void Build(int &x,int l,int r){
        if(x==0){
            x=++cnt;
            a[x].l=l;
            a[x].r=r;
            a[x].add=0;
            a[x].cov=-1;
        }
        if(l==r){
            a[x].maxx=val[l];
            return ;
        }
        int mid=(l+r)/2;
        Build(a[x].lson,l,mid);
        Build(a[x].rson,mid+1,r);
        pushup(x);
    }
    void coverdown(int x){
        if(a[x].cov!=-1){
            a[a[x].lson].maxx=a[x].cov;
            a[a[x].rson].maxx=a[x].cov;
            a[a[x].lson].cov=a[x].cov;
            a[a[x].rson].cov=a[x].cov;
            a[x].cov=-1;
        }
    }
    void plusdown(int x){
        if(a[x].add!=0){
            a[a[x].lson].maxx+=a[x].add;
            a[a[x].rson].maxx+=a[x].add;
            a[a[x].lson].add+=a[x].add;
            a[a[x].rson].add+=a[x].add;
            a[x].add=0;
        }
    }
    void cover(int x,int l,int r,int y){
        if(a[x].r<l||a[x].l>r)
            return ;
        if(l<=a[x].l&&a[x].r<=r){
            a[x].maxx=y;
            a[x].cov=y;
            a[x].add=0;
            return ;
        }
        coverdown(x);
        int mid=(a[x].l+a[x].r)/2;
        if(l<=mid) cover(a[x].lson,l,r,y);
        if(mid<r) cover(a[x].rson,l,r,y);
        pushup(x);
    }
    void plus(int x,int l,int r,int y){
        if(a[x].r<l||a[x].l>r)
            return ;
        if(l<=a[x].l&&a[x].r<=r){
            a[x].maxx+=y;
            a[x].add+=y;
            return ;
        }
        plusdown(x);
        int mid=(a[x].l+a[x].r)/2;
        if(l<=mid) plus(a[x].lson,l,r,y);
        if(mid<r) plus(a[x].rson,l,r,y);
        pushup(x);
    }
    long long ans=-9223372036854775808;
    void Ask(int x,int l,int r){
        if(a[x].r<l||a[x].l>r)
            return ;
        if(l<=a[x].l&&a[x].r<=r){
            ans=a[x].maxx>ans?a[x].maxx:ans;
            return ;
        }
        coverdown(x);
        plusdown(x);
        int mid=(a[x].l+a[x].r)/2;
        if(l<=mid) Ask(a[x].lson,l,r);
        if(mid<r) Ask(a[x].rson,l,r);
        pushup(x);
    }
    int main(){
        cin>>n>>q;
        for(int i=1;i<=n;i++)
            cin>>val[i];
        Build(Root,1,n);
        while(q--){
            int op;
            cin>>op;
            if(op==1){
                int l,r,x;
                cin>>l>>r>>x;
                cover(Root,l,r,x);
            }
            else if(op==2){
                int l,r,x;
                cin>>l>>r>>x;
                plus(Root,l,r,x);
            }
            else{
                int l,r;
                cin>>l>>r;
                ans=-9223372036854775808;
                Ask(Root,l,r);
                cout<<ans<<"\n";
            }
        }
        return 0;
    }
}
signed main(){
    //freopen("P1253_7.in","r",stdin);
    //freopen("new.out","w",stdout);
    ios::sync_with_stdio(false);
    cin.tie(0);
    Tree::main();
    return 0;
}