#include <iostream>

#include <cstdio>

#include <cstring>

#include <cstdlib>

#include <cmath>

#include <algorithm>

using namespace std;

const int MaxN = 100000 + 5, MaxM = 100000 * 16 * 16 + 5;

int n, m, f, a, b, c, Index, Ans;

int Root[MaxN * 4], Lc[MaxM], Rc[MaxM], Sum[MaxM], Lazy[MaxM];

inline int gmin(int a, int b) {

	return a < b ? a : b;

}

inline int gmax(int a, int b) {

	return a > b ? a : b;

}

int Get(int x, int s, int t, int l, int r) {

	if (l <= s && r >= t) return Sum[x];

	int p = 0, q = 0, m = (s + t) >> 1;

	if (l <= m) p = Get(Lc[x], s, m, l, r);

	if (r >= m + 1) q = Get(Rc[x], m + 1, t, l, r);

	return (p + q + Lazy[x] * (gmin(t, r) - gmax(s, l) + 1));

}

int GetKth(int l, int r, int k) {

	int s = 1, t = n * 2, m, x = 1, Temp;

	while (s != t) {

		m = (s + t) >> 1;

		if ((Temp = Get(Root[x << 1], 1, n, l, r)) >= k) {

			t = m; x = x << 1;

		}

		else {

			s = m + 1; x = x << 1 | 1; k -= Temp;

		}

	}

	return s;

}

void Insert(int &x, int s, int t, int l, int r) {

	if (x == 0) x = ++Index;

	if (l <= s && r >= t) {

		Sum[x] += t - s + 1;

		++Lazy[x];

		return;

	}

	int m = (s + t) >> 1;

	if (l <= m) Insert(Lc[x], s, m, l, r);

	if (r >= m + 1) Insert(Rc[x], m + 1, t, l, r);

	Sum[x] = Sum[Lc[x]] + Sum[Rc[x]] + Lazy[x] * (t - s + 1);

}

void Add(int l, int r, int Num) {

	int s = 1, t = n * 2, m, x = 1;

	while (s != t) {

		Insert(Root[x], 1, n, l, r);

		m = (s + t) >> 1;

		if (Num <= m) {

			t = m;

			x = x << 1;

		}

		else {

			s = m + 1;

			x = x << 1 | 1;

		}

	}

	Insert(Root[x], 1, n, l, r);

}

int main()

{

	scanf("%d%d", &n, &m);

	Index = 0;

	for (int i = 1; i <= m; ++i) {

		scanf("%d%d%d%d", &f, &a, &b, &c);

		if (f == 1) {

			c = -c + n + 1;

			Add(a, b, c);

		}

		else {

			Ans = GetKth(a, b, c);

			Ans = -Ans + n + 1;

			printf("%d\n", Ans);

		}

	}

	return 0;

}