#define DEBUG 0
#include <bits/stdc++.h>
using namespace std;
#if DEBUG
// basic debugging macros
int __i__,__j__;
#define printLine(l) for(__i__=0;__i__<l;__i__++){cout<<"-";}cout<<endl
#define printLine2(l,c) for(__i__=0;__i__<l;__i__++){cout<<c;}cout<<endl
#define printVar(n) cout<<#n<<": "<<n<<endl
#define printArr(a,l) cout<<#a<<": ";for(__i__=0;__i__<l;__i__++){cout<<a[__i__]<<" ";}cout<<endl
#define print2dArr(a,r,c) cout<<#a<<":\n";for(__i__=0;__i__<r;__i__++){for(__j__=0;__j__<c;__j__++){cout<<a[__i__][__j__]<<" ";}cout<<endl;}
#define print2dArr2(a,r,c,l) cout<<#a<<":\n";for(__i__=0;__i__<r;__i__++){for(__j__=0;__j__<c;__j__++){cout<<setw(l)<<setfill(' ')<<a[__i__][__j__]<<" ";}cout<<endl;}
// advanced debugging class
// debug 1,2,'A',"test";
class _Debug {
public:
template<typename T>
_Debug& operator,(T val) {
cout << val << endl;
return *this;
}
};
#define debug _Debug(),
#else
#define printLine(l)
#define printLine2(l,c)
#define printVar(n)
#define printArr(a,l)
#define print2dArr(a,r,c)
#define print2dArr2(a,r,c,l)
#define debug
#endif
// define
#define MAX_VAL 999999999
#define MAX_VAL_2 999999999999999999LL
#define EPS 1e-6
#define mp make_pair
#define pb push_back
// typedef
typedef unsigned int UI;
typedef long long int LLI;
typedef unsigned long long int ULLI;
typedef unsigned short int US;
typedef pair<int,int> pii;
typedef pair<LLI,LLI> plli;
typedef vector<int> vi;
typedef vector<LLI> vlli;
typedef vector<pii> vpii;
typedef vector<plli> vplli;
// ---------- END OF TEMPLATE ----------
int L[300000],R[300000];
int T[300000],A[300000],B[300000],C[300000],D[300000];
int l[300000],r[300000];
LLI ans[300000];
struct func {
LLI a,b,c,p;
plli eval(LLI x) {
if (x > p) return mp(b,c+x-p);
else return mp(max(b+x-p,a),c);
}
};
func com(func a,func b) {
func c;
c.a = b.eval(a.a).first,c.b = b.eval(a.b).first;
c.c = a.c+b.eval(a.a).second;
c.p = min(a.p,a.p-a.b+max(b.p,a.a));
return c;
}
func tree[1 << 20];
int build(int s,int e,int i) {
if (s == e) {
tree[i] = (func){l[s],r[s],0,r[s]};
return 0;
}
int mid = (s+e) / 2;
build(s,mid,2*i+1),build(mid+1,e,2*i+2);
tree[i] = com(tree[2*i+1],tree[2*i+2]);
return 0;
}
int update(int s,int e,int ai,int i) {
if ((s > ai) || (e < ai)) return 0;
else if (s == e) {
tree[i] = (func){l[s],r[s],0,r[s]};
return 0;
}
int mid = (s+e) / 2;
update(s,mid,ai,2*i+1),update(mid+1,e,ai,2*i+2);
tree[i] = com(tree[2*i+1],tree[2*i+2]);
return 0;
}
func query(int s,int e,int qs,int qe,int i) {
if ((s > qe) || (e < qs)) return (func){(LLI) -1e12,(LLI) 1e12,0,(LLI) 1e12};
else if ((s >= qs) && (e <= qe)) return tree[i];
int mid = (s+e) / 2;
return com(query(s,mid,qs,qe,2*i+1),query(mid+1,e,qs,qe,2*i+2));
}
int main() {
int i;
int N,Q;
scanf("%d %d",&N,&Q);
for (i = 0; i < N-1; i++) scanf("%d %d",&L[i],&R[i]);
for (i = 0; i < Q; i++) {
scanf("%d",&T[i]);
if (T[i] == 1) scanf("%d %d %d",&A[i],&B[i],&C[i]),A[i]--,ans[i] = -1;
else {
scanf("%d %d %d %d",&A[i],&B[i],&C[i],&D[i]),A[i]--,C[i]--;
if (A[i] == C[i]) ans[i] = max(B[i]-D[i],0);
}
}
int rr;
for (rr = 0; rr < 2; rr++) {
if (N == 1) break;
for (i = 0; i < N-1; i++) l[i] = L[i]-i,r[i] = R[i]-i-1;
build(0,N-2,0);
for (i = 0; i < Q; i++) {
if (T[i] == 1) {
l[A[i]] = B[i]-A[i],r[A[i]] = C[i]-A[i]-1;
update(0,N-2,A[i],0);
}
else if ((T[i] == 2) && (A[i] < C[i])) {
func f = query(0,N-2,A[i],C[i]-1,0);
plli p = f.eval(B[i]-A[i]);
if (p.first > (D[i]-C[i])) p.second += p.first-(D[i]-C[i]);
ans[i] = p.second;
}
}
reverse(L,L+N-1),reverse(R,R+N-1);
for (i = 0; i < Q; i++) {
if (T[i] == 1) A[i] = N-2-A[i];
else if (T[i] == 2) A[i] = N-1-A[i],C[i] = N-1-C[i];
}
}
for (i = 0; i < Q; i++) {
if (ans[i] != -1) printf("%lld\n",ans[i]);
}
return 0;
}
