#include <cstdio>

#include <iostream>

#include <algorithm>

#define N 50010

#define LL long long

using namespace std;

int n, m, t, cnt;

LL sum[N * 200];

int opt[N], a[N], b[N], c[N], g[N], add[N * 200], ls[N * 200], rs[N * 200], root[N << 2];

inline int read()

{

	int x = 0, f = 1;

	char ch = getchar();

	for(; !isdigit(ch); ch = getchar()) if(ch == '-') f = -1;

	for(; isdigit(ch); ch = getchar()) x = (x << 1) + (x << 3) + ch - '0';

	return x * f;

}

inline void insert2(int &now, int l, int r, int x, int y)

{

	if(!now) now = ++cnt;

	if(x <= l && r <= y)

	{

		add[now]++;

		sum[now] += r - l + 1;

		return;

	}

	int mid = (l + r) >> 1;

	if(x <= mid) insert2(ls[now], l, mid, x, y);

	if(mid < y) insert2(rs[now], mid + 1, r, x, y);

	sum[now] = sum[ls[now]] + sum[rs[now]] + (LL)(r - l + 1) * add[now];

}

inline void insert1(int now, int l, int r, int d, int x, int y)

{

	insert2(root[now], 1, n, x, y);

	if(l == r) return;

	int mid = (l + r) >> 1;

	if(d <= mid) insert1(now << 1, l, mid, d, x, y);

	else insert1(now << 1 | 1, mid + 1, r, d, x, y);

}

inline LL query2(int now, int l, int r, int x, int y)

{

	if(x <= l && r <= y) return sum[now];

	LL tmp = 0;

	int mid = (l + r) >> 1;

	if(x <= mid) tmp += query2(ls[now], l, mid, x, y);

	if(mid < y) tmp += query2(rs[now], mid + 1, r, x, y);

	return tmp + (LL)(min(r, y) - max(l, x) + 1) * add[now];

}

inline int query1(int now, int l, int r, LL d, int x, int y)

{

	if(l == r) return l;

	int mid = (l + r) >> 1;

	LL tmp = query2(root[now << 1 | 1], 1, n, x, y);

	if(tmp < d) return query1(now << 1, l, mid, d - tmp, x, y);

	else return query1(now << 1 | 1, mid + 1, r, d, x, y);

}

int main()

{

	int i;

	n = read();

	m = read();

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

	{

		opt[i] = read();

		a[i] = read(), b[i] = read(), c[i] = read();

		if(opt[i] == 1) g[++t] = c[i];

	}

	sort(g + 1, g + t + 1);

	t = unique(g + 1, g + t + 1) - g - 1;

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

		if(opt[i] == 1)

		{

			c[i] = lower_bound(g + 1, g + t + 1, c[i]) - g;

			insert1(1, 1, t, c[i], a[i], b[i]);

		}

		else printf("%d\n", g[query1(1, 1, t, c[i], a[i], b[i])]);

	return 0;

}