#include <bits/stdc++.h>
using namespace std;
const int maxn = 2e5 + 5;
int tr[maxn<<2], n, q;

#define lson l, mid, rt<<1
#define rson mid+1, r, rt<<1|1
void push_up(int rt) {
	tr[rt] = tr[rt<<1] + tr[rt<<1|1];
}
void update(int p, int l, int r, int rt) {
	if (l == r) {
		tr[rt] = 1;
		return;
	}
	int mid = (l + r) / 2;
	(p <= mid) ? update(p, lson) : update(p, rson);
	push_up(rt);
}
int query(int L, int R, int l, int r, int rt) {
	if (L <= l && r <= R)
		return tr[rt];
	int mid = (l + r) / 2, res = 0;
	if (L <= mid) res += query(L, R, lson);
	if (R > mid) res += query(L, R, rson);
	return res;
}
int find(int L, int R, int k, int l, int r, int rt) {
	if (l == r)
		return l;
	int mid = (l + r) / 2;
	if (L <= mid) { // [l , mid]
		int m = query(L, R, lson);
		if (m >= k)
			return find(L, R, k, lson);
		return find(L, R, k-m, rson);
	}
	return find(L, R, k, rson);
}
int main() {
	scanf("%d%d", &n, &q);
	while (q--) {
		int op;
		scanf("%d", &op);
		if (op == 1) {
			int x;
			scanf("%d", &x);
			update(x, 1, n, 1);
		}
		else {
			int l, r, k;
			scanf("%d%d%d", &l, &r, &k);
			printf("%d\n", find(l, r, k, 1, n, 1));
		}
	}
	return 0;
}