#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;
#define pb push_back
#define ff first
#define ss second
struct DS{
int n;
vector<int> l, r;
DS(int ns){
n = ns;
l.resize(n);
r.resize(n);
}
void upd(int p, int s, int e){
l[p] = s; r[p] = e;
}
ll get(int a, int b, int c, int d){
ll out = 0;
for (int i = a; i < c; i++){
b = max(b, l[i]);
if (b < r[i]){
b++;
}
else {
out += (b - r[i] + 1);
b = r[i];
}
}
if (b > d) out += (b - d);
return out;
}
};
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int n, q; cin>>n>>q;
vector<int> l(n), r(n);
for (int i = 1; i < n; i++){
cin>>l[i]>>r[i];
}
DS T1(n), T2(n);
for (int i = 1; i < n; i++){
T1.upd(i, l[i], r[i]);
T2.upd(n - i, l[i], r[i]);
}
while (q--){
int t; cin>>t;
if (t == 1){
int p, s, e; cin>>p>>s>>e;
T1.upd(p, s, e);
T2.upd(n - p, s, e);
}
else {
int a, b, c, d; cin>>a>>b>>c>>d;
if (a <= c){
cout<<T1.get(a, b, c, d)<<"\n";
}
else {
cout<<T2.get(n - a + 1, b, n - c + 1, d)<<"\n";
}
}
}
}
