#include<bits/stdc++.h>
using namespace std;
#define ll long long
const int N = 3e5 + 5;
int n, q, L[2][N], R[2][N];
struct node{
ll l, r, pos, cost;
} st[2][4 * N];
node merge(node a, node b){
node res;
if(a.l == a.r){
if(b.l == b.r){
res.l = res.r = a.l;
res.pos = b.pos;
res.cost = a.cost + b.cost + max(0LL, a.pos - b.l);
} else {
res.l = res.r = a.l;
res.pos = min(b.r, max(b.l, a.pos));
res.cost = a.cost + b.cost + max(0LL, a.pos - b.r);
}
} else {
if(b.l == b.r){
if(a.r < b.l){
res.l = res.r = a.r;
res.pos = b.pos;
res.cost = a.cost + b.cost;
} else if(a.l > b.l){
res.l = res.r = a.l;
res.pos = b.pos;
res.cost = a.cost + b.cost + a.pos - b.l;
} else {
res.l = res.r = b.l;
res.pos = b.pos;
res.cost = a.cost + b.cost;
}
} else {
if(a.r < b.l){
res.l = res.r = a.r;
res.pos = b.l;
res.cost = a.cost + b.cost;
} else if(a.l > b.r){
res.l = res.r = a.l;
res.pos = b.r;
res.cost = a.cost + b.cost + a.l - b.r;
} else {
res.l = max(a.l, b.l);
res.r = min(a.r, b.r);
res.pos = res.l;
res.cost = 0;
}
}
}
return res;
}
void build(int id, int l, int r, int t){
if(l == r){
st[t][id].l = L[t][l];
st[t][id].r = R[t][l];
st[t][id].pos = L[t][l];
st[t][id].cost = 0;
return;
}
int mid = (l + r) >> 1;
build(id << 1, l, mid, t);
build(id << 1 | 1, mid + 1, r, t);
st[t][id] = merge(st[t][id << 1], st[t][id << 1 | 1]);
}
void update(int id, int l, int r, int i, node x, int t){
if(l > i || r < i){
return;
}
if(l == r){
st[t][id] = x;
return;
}
int mid = (l + r) >> 1;
update(id << 1, l, mid, i, x, t);
update(id << 1 | 1, mid + 1, r, i, x, t);
st[t][id] = merge(st[t][id << 1], st[t][id << 1 | 1]);
}
node get(int id, int l, int r, int i, int j, int t){
if(l > j || r < i || i > j){
return {(ll)-1e9, (ll)1e9, (ll)-1e9, 0};
}
if(l >= i && r <= j){
return st[t][id];
}
int mid = (l + r) >> 1;
return merge(get(id << 1, l, mid, i, j, t), get(id << 1 | 1, mid + 1, r, i, j, t));
}
int main() {
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
cin >> n >> q;
if(n == 1){
while(q--){
int t, a, b, c, d;
cin >> t;
if(t == 2){
cin >> a >> b >> c >> d;
cout << max(0, b - d) << "\n";
}
}
return 0;
}
for(int i = 1; i < n; i++){
cin >> L[0][i] >> R[0][i];
L[1][n - i] = L[0][i];
R[1][n - i] = R[0][i];
}
for(int i = 1; i < n; i++){
L[0][i] -= i; R[0][i] -= i + 1;
L[1][i] -= i; R[1][i] -= i + 1;
}
build(1, 1, n - 1, 0);
build(1, 1, n - 1, 1);
while(q--){
int t;
cin >> t;
if(t == 1){
int p, s, e;
cin >> p >> s >> e;
node tmp = {s - p, e - p - 1, s - p, 0};
update(1, 1, n - 1, p, tmp, 0);
p = n - p;
tmp = {s - p, e - p - 1, s - p, 0};
update(1, 1, n - 1, p, tmp, 1);
} else {
int a, b, c, d;
cin >> a >> b >> c >> d;
if(a == c){
cout << max(0, b - d) << "\n";
} else {
int ck = 0;
if(a > c){
a = n - a + 1; c = n - c + 1;
ck = 1;
}
node res = get(1, 1, n - 1, a, c - 1, ck);
b -= a; d -= c;
res = merge({b, b, b, 0}, res);
cout << res.cost + max(0LL, res.pos - d) << "\n";
}
}
}
}
