#include <bits/stdc++.h>
#define ll long long
#define task ""
using namespace std;
const int maxn = 3e5 + 2, inf = 1e9 + 7;
ll n, q, L[maxn], R[maxn], tp, a, b, c, d, p, s, e;
struct hihi
{
bool tp;
ll l, r, leap;
}st[2][2 * maxn];
struct SegmentTree
{
hihi merge (hihi A, hihi B)
{
hihi C;
C.leap = A.leap + B.leap;
int haha = (A.tp << 1) + B.tp;
if (haha == 0)
{
if (max(A.l, B.l) <= min(A.r, B.r))
{
C.tp = 0;
C.l = max(A.l, B.l);
C.r = min(A.r, B.r);
}
else if (A.r < B.l)
{
C.tp = 1;
C.l = A.r;
C.r = B.l;
}
else if (A.l > B.r)
{
C.tp = 1;
C.l = A.l;
C.r = B.r;
C.leap += A.l - B.r;
}
}
else if (haha == 1)
{
C.tp = 1;
C.r = B.r;
if (A.l > B.l)
{
C.l = A.l;
C.leap += A.l - B.l;
}
else if (A.r < B.l)
{
C.l = A.r;
}
else
{
C.l = B.l;
}
}
else if (haha == 2)
{
C.tp = 1;
C.l = A.l;
if (A.r > B.r)
{
C.r = B.r;
C.leap += A.r - B.r;
}
else if (A.r < B.l)
{
C.r = B.l;
}
else
{
C.r = A.r;
}
}
else
{
C.tp = 1;
C.l = A.l;
C.r = B.r;
C.leap += max(0LL, A.r - B.l);
}
return C;
}
void build (bool tp, int node, int l, int r)
{
if (l == r)
{
if (tp == 0)
{
st[tp][node].tp = 0;
st[tp][node].l = L[l] - l;
st[tp][node].r = R[l] - (l + 1);
st[tp][node].leap = 0;
}
else
{
st[tp][node].tp = 0;
st[tp][node].l = L[n - l] - l;
st[tp][node].r = R[n - l] - (l + 1);
st[tp][node].leap = 0;
}
return;
}
int m = (l + r)/2;
build(tp, node + 1, l, m);
build(tp, node + 2 * (m - l + 1), m + 1, r);
st[tp][node] = merge(st[tp][node + 1], st[tp][node + 2 * (m - l + 1)]);
}
void upd (int tp, int node, int l, int r, int idx, int L, int R)
{
if (l == r)
{
st[tp][node].tp = 0;
st[tp][node].l = L - l;
st[tp][node].r = R - (l + 1);
st[tp][node].leap = 0;
return;
}
int m = (l + r)/2;
if (idx <= m) upd(tp, node + 1, l, m, idx, L, R);
else upd(tp, node + 2 * (m - l + 1), m + 1, r, idx, L, R);
st[tp][node] = merge(st[tp][node + 1], st[tp][node + 2 * (m - l + 1)]);
}
hihi get (int tp, int node, int l, int r, int cl, int cr)
{
if (cr < l || r < cl) return {0, -inf, inf, 0};
if (cl <= l && r <= cr) return st[tp][node];
int m = (l + r)/2;
return merge(get(tp, node + 1, l, m, cl, cr), get(tp, node + 2 * (m - l + 1), m + 1, r, cl, cr));
}
}str[2];
int main()
{
//freopen(task".INP", "r", stdin);
//freopen(task".OUT", "w", stdout);
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
cin >> n >> q;
for (int i = 1; i < n; i++) cin >> L[i] >> R[i];
if (n > 1)
{
str[0].build(0, 1, 1, n - 1);
str[1].build(1, 1, 1, n - 1);
}
for (int i = 1; i <= q; i++)
{
cin >> tp;
if (tp == 1)
{
cin >> p >> s >> e;
str[0].upd(0, 1, 1, n - 1, p, s, e);
str[1].upd(1, 1, 1, n - 1, n - p, s, e);
}
else
{
cin >> a >> b >> c >> d;
if (a == c) cout << max(0LL, b - d) << '\n';
else if (a < c)
{
b -= a;
d -= c;
hihi owo = str[0].get(0, 1, 1, n - 1, a, c - 1);
ll ans = 0, cur = 0;
if (owo.tp == 0)
{
if (b < owo.l)
{
ans += owo.leap;
cur = owo.l;
}
else if (b > owo.r)
{
ans += owo.leap + b - owo.r;
cur = owo.r;
}
else
{
ans += owo.leap;
cur = b;
}
}
else
{
cur = owo.r;
if (b > owo.l)
{
ans += owo.leap + b - owo.l;
}
else
{
ans += owo.leap;
}
}
cout << ans + max(0LL, cur - d) << '\n';
}
else if (a > c)
{
a = n + 1 - a;
c = n + 1 - c;
b -= a;
d -= c;
hihi owo = str[1].get(1, 1, 1, n - 1, a, c - 1);
ll ans = 0, cur = 0;
if (owo.tp == 0)
{
if (b < owo.l)
{
ans += owo.leap;
cur = owo.l;
}
else if (b > owo.r)
{
ans += owo.leap + b - owo.r;
cur = owo.r;
}
else
{
ans += owo.leap;
cur = b;
}
}
else
{
cur = owo.r;
if (b > owo.l)
{
ans += owo.leap + b - owo.l;
}
else
{
ans += owo.leap;
}
}
cout << ans + max(0LL, cur - d) << '\n';
}
}
}
}
