#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
struct Node {
pair<ll, ll> lin, lout;
ll ldp;
};
void merge(Node& ret, Node& l, Node& r) {
ret.lin = l.lin;
ret.lout = l.lout;
ret.ldp = l.ldp + r.ldp;
if (ret.lin.first < ret.lin.second) {
if (ret.lout.second <= r.lin.first) {
ret.lin.first = ret.lin.second;
ret.lout.first = ret.lout.second;
}
else if (ret.lout.first >= r.lin.second) {
ret.lin.second = ret.lin.first;
ret.lout.second = ret.lout.first;
}
else {
if (ret.lout.first < r.lin.first) {
ret.lin.first += r.lin.first - ret.lout.first;
ret.lout.first = r.lin.first;
}
if (ret.lout.second > r.lin.second) {
ret.lin.second += r.lin.second - ret.lout.second;
ret.lout.second = r.lin.second;
}
if (ret.lin.first < ret.lin.second) {
ret.lout.first += r.lout.first - r.lin.first;
ret.lout.second += r.lout.first - r.lin.first;
}
}
}
if (ret.lin.first == ret.lin.second) {
if (ret.lout.first > r.lin.second) ret.ldp += ret.lout.first - r.lin.second;
if (r.lin.first < r.lin.second) {
if (ret.lout.first > r.lin.second) ret.lout.first = ret.lout.second = r.lin.second;
else if (ret.lout.second < r.lin.first) ret.lout.first = ret.lout.second = r.lin.first;
ret.lout.first += r.lout.first - r.lin.first;
ret.lout.second += r.lout.first - r.lin.first;
}
else ret.lout = r.lout;
}
}
ll L[300000], R[300000];
Node lseg[1048576], rseg[1048576];
void init(int t1, int t2, int idx) {
if (t1 == t2) {
lseg[idx].lin = rseg[idx].lin = {L[t1], R[t1]};
lseg[idx].lout = rseg[idx].lout = {L[t1] + 1, R[t1] + 1};
lseg[idx].ldp = rseg[idx].ldp = 0;
return;
}
int mid = (t1 + t2) >> 1;
init(t1, mid, idx << 1);
init(mid + 1, t2, idx << 1 | 1);
merge(lseg[idx], lseg[idx << 1], lseg[idx << 1 | 1]);
merge(rseg[idx], rseg[idx << 1 | 1], rseg[idx << 1]);
}
void update(int t1, int t2, int q, int idx) {
if (q < t1 || t2 < q) return;
if (t1 == t2) {
lseg[idx].lin = rseg[idx].lin = {L[t1], R[t1]};
lseg[idx].lout = rseg[idx].lout = {L[t1] + 1, R[t1] + 1};
return;
}
int mid = (t1 + t2) >> 1;
update(t1, mid, q, idx << 1);
update(mid + 1, t2, q, idx << 1 | 1);
merge(lseg[idx], lseg[idx << 1], lseg[idx << 1 | 1]);
merge(rseg[idx], rseg[idx << 1 | 1], rseg[idx << 1]);
}
Node query(int t1, int t2, int q1, int q2, bool isl, int idx) {
if (q1 <= t1 && t2 <= q2) return isl ? lseg[idx] : rseg[idx];
int mid = (t1 + t2) >> 1;
if (q2 <= mid) return query(t1, mid, q1, q2, isl, idx << 1);
if (mid + 1 <= q1) return query(mid + 1, t2, q1, q2, isl, idx << 1 | 1);
Node l = query(t1, mid, q1, q2, isl, idx << 1), r = query(mid + 1, t2, q1, q2, isl, idx << 1 | 1);
Node ret;
isl ? merge(ret, l, r) : merge(ret, r, l);
return ret;
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
int N, Q;
cin >> N >> Q;
for (int i = 0; i < N - 1; i++) {
cin >> L[i] >> R[i];
R[i]--;
}
if (N == 1) {
while (Q--) {
int T;
cin >> T;
if (T == 1) {
int P;
ll S, E;
cin >> P >> S >> E;
}
else {
int A, C;
ll B, D;
cin >> A >> B >> C >> D;
if (B <= D) cout << "0\n";
else cout << B - D << '\n';
}
}
return 0;
}
init(0, N - 2, 1);
while (Q--) {
int T;
cin >> T;
if (T == 1) {
int P;
ll S, E;
cin >> P >> S >> E;
L[--P] = S;
R[P] = E - 1;
update(0, N - 2, P, 1);
}
else {
int A, C;
ll B, D;
cin >> A >> B >> C >> D;
if (--A == --C) {
if (B <= D) cout << "0\n";
else cout << B - D << '\n';
}
else {
Node qval = query(0, N - 2, min(A, C), max(A, C) - 1, A < C, 1);
//cout << qval.lin.first << ' ' << qval.lin.second << " -> " << qval.lout.first << ' ' << qval.lout.second << " = " << qval.ldp << '\n';
ll ans = qval.ldp;
if (B > qval.lin.second) {
ans += B - qval.lin.second;
B = qval.lin.second;
}
else if (B < qval.lin.first) B = qval.lin.first;
B += qval.lout.first - qval.lin.first;
if (B > D) ans += B - D;
cout << ans << '\n';
}
}
}
}
