#include <bits/stdc++.h>
typedef long long ll;
int main() {
std::ios_base::sync_with_stdio(false);
std::cin.tie(nullptr);
int n, q;
std::cin >> n >> q;
std::vector<ll> l(n - 1), r(n - 1);
for (int i = 0; i < n - 1; ++i) {
std::cin >> l[i] >> r[i];
}
while (q--) {
int t;
std::cin >> t;
if (t == 1) {
int p, s, e;
std::cin >> p >> s >> e;
l[p - 1] = s, r[p - 1] = e;
} else {
ll a, b, c, d;
std::cin >> a >> b >> c >> d;
ll ans = 0;
--a, --c;
for (int i = a < c ? a : a - 1;
(a < c and i < c) or (a > c and i >= c);) {
if (b < l[i]) {
b = l[i];
} else if (b > r[i] - 1) {
ans += b - (r[i] - 1);
b = r[i] - 1;
}
b++;
i += a < c ? 1 : -1;
}
if (b > d) {
ans += b - d;
b = d;
}
std::cout << ans << '\n';
}
}
}
