#include <bits/stdc++.h>
using namespace std;
#define x first
#define y second
#define all(x) x.begin(), x.end()
#define len(x) (int)(x).size()
using pii = pair<int, int>;
template <typename T, typename T2>
ostream &operator<<(ostream &o, const pair<T, T2> &p);
template <typename T>
ostream &operator<<(ostream &o, const vector<T> &v);
template <typename T, typename T2>
ostream &operator<<(ostream &o, const pair<T, T2> &p)
{
return o << "(" << p.x << "," << p.y << ")";
}
template <typename T>
ostream &operator<<(ostream &o, const vector<T> &t)
{
o << "[";
for (int i{}; auto u : t)
o << (i++ ? "," : "") << u;
return o << "]";
}
int nxt()
{
int x;
cin >> x;
return x;
}
int n, q;
vector<pii> segments;
const int BASE = 1 << 19;
int query(int a, int b, int c, int d)
{
int power_uses = 0;
int height = b;
// cout << vector({a, b, c, d}) << "\n";
vector<pii> path;
for (int i = a - 1; i >= c; i--)
{
path.push_back(segments[i]);
}
for (int i = a; i < c; i++)
{
path.push_back(segments[i]);
}
path.push_back({d, d + 1});
// cout << path << "\n";
for (auto [x, y] : path)
{
height = max(height, x);
if(height >= y)
{
power_uses += height - y + 1;
// cout << x << " " << y << " " << height - y + 1 << " obnizanie\n";
height = y - 1;
}
height += 1;
}
return power_uses;
}
void update(int p, int s, int e) // update semgent
{
segments[p] = {s, e};
}
int main()
{
// ios::sync_with_stdio(0), cin.tie(0);
n = nxt(), q = nxt();
segments.push_back({0, 0});
for (int i = 0; i < n - 1; i++)
segments.push_back({nxt(), nxt()});
for (int i = 0; i < q; i++)
{
if (nxt() == 1)
{
int p = nxt(),
s = nxt(),
e = nxt();
update(p, s, e);
}
else
{
int a = nxt(),
b = nxt(),
c = nxt(),
d = nxt();
cout << query(a, b, c, d) << "\n";
}
}
}
/*
3 3
0 5
0 5
2 1 3 3 3
1 2 0 1
2 1 3 3 3
*/
