#include<bits/stdc++.h>
using namespace std;
int a[500001],n,m,ans=0;
int x,y,k,p;
struct q{
	long long l,r,sum,lazy;
}tree[500001];
long long maxx(long long a,long long b){
	if(a<b)return b;
	else return a;
}
inline int read(){
	int x=0,f=1;char ch=getchar();
	while (!isdigit(ch)){if (ch=='-') f=-1;ch=getchar();}
	while (isdigit(ch)){x=x*10+ch-48;ch=getchar();}
	return x*f;
}
void build(int x,int l,int r){
	tree[x].l=l,tree[x].r=r;
	if(l==r){tree[x].sum=a[l];return;}
	int mid=(l+r)/2;
	build(2*x,l,mid),build(2*x+1,mid+1,r);
	tree[x].sum=maxx(tree[2*x].sum,tree[2*x+1].sum);
}
void add(int x,int l,int r,int k){
	//cout<<x<<" "<<l<<" "<<r<<" "<<k<<endl;
	if(tree[x].l>=l&&tree[x].r<=r){
		tree[x].lazy+=k;
		tree[x].sum+=k;
		return;
	}
	if(tree[x].lazy){
		tree[2*x].lazy+=tree[x].lazy;
		tree[2*x].sum+=tree[x].lazy;
		tree[2*x+1].lazy+=tree[x].lazy;
		tree[2*x+1].sum+=tree[x].lazy;
		tree[x].lazy=0;
	}
	int mid=(tree[x].l+tree[x].r)/2;
	if(mid>=l)add(2*x,l,r,k);
	if(mid+1<=r)add(2*x+1,l,r,k);
	tree[x].sum=maxx(tree[2*x].sum,tree[2*x+1].sum);
}
long long get(int x,int l,int r){
	if(tree[x].l>=l&&tree[x].r<=r)return tree[x].sum;
	if(tree[x].lazy){
		tree[2*x].lazy+=tree[x].lazy;
		tree[2*x].sum+=tree[x].lazy;
		tree[2*x+1].lazy+=tree[x].lazy;
		tree[2*x+1].sum+=tree[x].lazy;
		tree[x].lazy=0;
	}
	long long sum=-1e18;
	int mid=(tree[x].l+tree[x].r)/2;
	if(mid>=l)sum=maxx(sum,get(2*x,l,r));
	if(mid+1<=r)sum=maxx(sum,get(2*x+1,l,r));
	return sum;
}
int main(){
	freopen("max.in","r",stdin);
	freopen("max.out","w",stdout);
	n=read(),m=read();
	for(int i=1;i<=n;i++)a[i]=read();
	build(1,1,n);
	for(int i=1;i<=m;i++){
		cin>>p;
		if(p==1){
			x=read(),y=read(),k=read();
			add(1,x,y,k);
			//for(int i=1;i<=9;i++)cout<<tree[i].lazy<<" "<<tree[i].sum<<endl;
		}
		if(p==2){
			x=read(),y=read();
			cout<<get(1,x,y)<<endl;
		}
	}
	return 0;
}