# include <bits/stdc++.h>
using namespace std;
typedef long long ll;
int n,q,L[300010],R[300010];
ll ans[300010];
struct Query{int op,a,b,c,d;}que[300010];
struct node
{
	int L,R,typ,x;
	ll y;
	node(int _L=0,int _R=0):L(_L),R(_R),typ(0),y(0){}
	int pos(int t)const{return max(min(t,R),L);}
	ll calc(int t)const{return typ?max(t-x,0)+y:max(t-R,0);}
	node operator+(const node &a)const
	{
		node ans;
		if(typ || a.typ || max(L,a.L)>min(R,a.R))
		{
			ans.typ=1;
			ans.L=a.pos(L);ans.R=a.pos(R);
			assert(pos(a.L)==pos(a.R));
			ans.x=pos(a.L);ans.y=a.calc(ans.x)+y;
		}
		else
		{
			ans.typ=0;
			ans.L=max(L,a.L);ans.R=min(R,a.R);
		}
		return ans;
	}
}val[1100000];
void build(int rt,int l,int r)
{
	if(l==r) return val[rt]=node(L[l]-l,R[l]-1-l),void();
	int mid=(l+r)/2;
	build(rt*2,l,mid);build(rt*2+1,mid+1,r);
	val[rt]=val[rt*2]+val[rt*2+1];
}
void update(int rt,int l,int r,int x,int y,int z)
{
	if(l==r) return val[rt]=node(y-x,z-1-x),void();
	int mid=(l+r)/2;
	if(x<=mid) update(rt*2,l,mid,x,y,z);
	else update(rt*2+1,mid+1,r,x,y,z);
	val[rt]=val[rt*2]+val[rt*2+1];
}
node query(int rt,int l,int r,int x,int y)
{
	if(x<=l && r<=y) return val[rt];
	int mid=(l+r)/2;
	if(y<=mid) return query(rt*2,l,mid,x,y);
	else if(x>mid) return query(rt*2+1,mid+1,r,x,y);
	else return query(rt*2,l,mid,x,y)+query(rt*2+1,mid+1,r,x,y);
}
void solve()
{
	build(1,1,n-1);
	for(int i=1;i<=q;i++)
		if(que[i].op==1) update(1,1,n-1,que[i].a,que[i].b,que[i].c);
		else if(que[i].a<que[i].c)
		{
			int x=que[i].a,y=que[i].c,t1=que[i].b-x,t2=que[i].d-y;
			node v=query(1,1,n-1,x,y-1);
			ans[i]=v.calc(t1)+max(v.pos(t1)-t2,0);
		}
}
int main()
{
	cin>>n>>q;
	for(int i=1;i<n;i++) scanf("%d%d",&L[i],&R[i]);
	for(int i=1;i<=q;i++)
	{
		scanf("%d%d%d%d",&que[i].op,&que[i].a,&que[i].b,&que[i].c);
		if(que[i].op==2) scanf("%d",&que[i].d);
	}
	for(int i=1;i<=q;i++)
		if(que[i].a==que[i].c) ans[i]=max(que[i].b-que[i].d,0);
	solve();
	reverse(L+1,L+n);reverse(R+1,R+n);
	for(int i=1;i<=n;i++)
		if(que[i].op==1) que[i].a=n-que[i].a;
		else que[i].a=n-que[i].a+1,que[i].c=n-que[i].c+1;
	solve();
	for(int i=1;i<=q;i++)
		if(que[i].op==2) printf("%lld\n",ans[i]);
	return 0;
}