#include <bits/stdc++.h>
using namespace std;
const long long INF = 1LL * 1e18;
struct Node { long long ll, lr, rl, rr; };
Node comb(Node X, Node Y) {
Node ret;
ret.ll = max(X.ll + Y.rl, X.lr + Y.ll);
ret.lr = max({X.ll + Y.rr, X.lr + Y.lr, 0LL});
ret.rl = max({X.rl + Y.rl, X.rr + Y.ll, 0LL});
ret.rr = max(X.rl + Y.rr, X.rr + Y.lr);
return ret;
}
struct segtree {
vector<Node> T;
segtree(int sz) {
T.resize(4*sz);
}
Node get(int idx, int s, int e, int l, int r) {
if(r < s || e < l) return {-INF, 0, 0, -INF};
if(l <= s && e <= r) return T[idx];
int m = s+e >> 1;
return comb(get(idx*2, s, m, l, r), get(idx*2+1, m+1, e, l, r));
}
void upd(int idx, int s, int e, int p, int S, int E) {
if(p < s || e < p) return;
if(s == e) {
T[idx].ll = S;
T[idx].rr = -E;
T[idx].lr = T[idx].rl = 0;
return;
}
int m = s+e >> 1;
upd(idx*2, s, m, p, S, E);
upd(idx*2+1, m+1, e, p, S, E);
T[idx] = comb(T[idx*2], T[idx*2+1]);
}
};
int L[300009], R[300009];
int main() {
int N, Q; scanf("%d%d",&N,&Q);
for(int i=1; i<N; i++) scanf("%d%d",&L[i],&R[i]);
segtree AC(N), CA(N);
for(int i=1; i<N; i++) AC.upd(1, 1, N-1, i, L[i] - i, R[i] - 1 - i);
for(int i=1; i<N; i++) CA.upd(1, 1, N-1, i, L[N-i] - i, R[N-i] - 1 - i);
while(Q--) {
int ty; scanf("%d",&ty);
if(ty == 1) {
int P, S, E; scanf("%d%d%d",&P,&S,&E);
AC.upd(1, 1, N-1, P, S - P, E - 1 - P);
P = N - P;
CA.upd(1, 1, N-1, P, S - P, E - 1 - P);
}
if(ty == 2) {
int A, B, C, D; scanf("%d%d%d%d",&A,&B,&C,&D);
if(A < C) {
B -= A; D -= C;
Node st = {B, 0, -INF, -B}, en = {D, 0, -INF, -D};
printf("%lld\n", comb(comb(st, AC.get(1, 1, N-1, A, C-1)), en).lr);
}
if(C < A) {
A = N - A + 1; C = N - C + 1;
B -= A; D -= C;
Node st = {B, 0, -INF, -B}, en = {D, 0, -INF, -D};
printf("%lld\n", comb(comb(st, CA.get(1, 1, N-1, A, C-1)), en).lr);
}
if(A == C) printf("%lld\n", 1LL * max(B - D, 0));
}
}
return 0;
}
